1
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Edwards B, Deaconu DA, Murgatroyd PAE, Buchberger S, Antonelli T, Halliday D, Siemann GR, Zivanovic A, Trzaska L, Rajan A, Abarca Morales E, Mayoh DA, Hall AE, Belosludov RV, Watson MD, Kim TK, Biswas D, Lee TL, Polley CM, Carbone D, Leandersson M, Balakrishnan G, Bahramy MS, King PDC. Chemical Trends of the Bulk and Surface Termination-Dependent Electronic Structure of Metal-Intercalated Transition Metal Dichalcogenides. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2024; 36:7117-7126. [PMID: 39156710 PMCID: PMC11325556 DOI: 10.1021/acs.chemmater.4c00824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 07/09/2024] [Accepted: 07/10/2024] [Indexed: 08/20/2024]
Abstract
The addition of metal intercalants into the van der Waals gaps of transition metal dichalcogenides has shown great promise as a method for controlling their functional properties. For example, chiral helimagnetic states, current-induced magnetization switching, and a giant valley-Zeeman effect have all been demonstrated, generating significant renewed interest in this materials family. Here, we present a combined photoemission and density-functional theory study of three such compounds: , , and , to investigate chemical trends of the intercalant species on their bulk and surface electronic structure. Our resonant photoemission measurements indicate increased hybridization with the itinerant NbS2-derived conduction states with increasing atomic number of the intercalant, leading to pronounced mixing of the nominally localized intercalant states at the Fermi level. Using spatially and angle-resolved photoemission spectroscopy, we show how this impacts surface-termination-dependent charge transfers and leads to the formation of new dispersive states of mixed intercalant-Nb character at the Fermi level for the intercalant-terminated surfaces. This provides an explanation for the origin of anomalous states previously reported in this family of compounds and paves the way for tuning the nature of the magnetic interactions in these systems via control of the hybridization of the magnetic ions with the itinerant states.
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Affiliation(s)
- Brendan Edwards
- SUPA,
School of Physics and Astronomy, University
of St Andrews, St Andrews KY16 9SS, U.K.
| | - Darius-A. Deaconu
- Department
of Physics and Astronomy, University of
Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | | | - Sebastian Buchberger
- SUPA,
School of Physics and Astronomy, University
of St Andrews, St Andrews KY16 9SS, U.K.
- Max
Planck Institute for Chemical Physics of Solids, Nöthnitzer Strasse 40, Dresden 01187, Germany
| | - Tommaso Antonelli
- SUPA,
School of Physics and Astronomy, University
of St Andrews, St Andrews KY16 9SS, U.K.
| | - Daniel Halliday
- SUPA,
School of Physics and Astronomy, University
of St Andrews, St Andrews KY16 9SS, U.K.
- Diamond
Light Source Ltd, Harwell
Science and Innovation Campus, Didcot OX11 0DE, U.K.
| | - Gesa-R. Siemann
- SUPA,
School of Physics and Astronomy, University
of St Andrews, St Andrews KY16 9SS, U.K.
| | - Andela Zivanovic
- SUPA,
School of Physics and Astronomy, University
of St Andrews, St Andrews KY16 9SS, U.K.
- Max
Planck Institute for Chemical Physics of Solids, Nöthnitzer Strasse 40, Dresden 01187, Germany
| | - Liam Trzaska
- SUPA,
School of Physics and Astronomy, University
of St Andrews, St Andrews KY16 9SS, U.K.
| | - Akhil Rajan
- SUPA,
School of Physics and Astronomy, University
of St Andrews, St Andrews KY16 9SS, U.K.
| | - Edgar Abarca Morales
- SUPA,
School of Physics and Astronomy, University
of St Andrews, St Andrews KY16 9SS, U.K.
- Max
Planck Institute for Chemical Physics of Solids, Nöthnitzer Strasse 40, Dresden 01187, Germany
| | - Daniel A. Mayoh
- Department
of Physics, University of Warwick, Coventry CV4 7AL, U.K.
| | - Amelia E. Hall
- Department
of Physics, University of Warwick, Coventry CV4 7AL, U.K.
| | | | - Matthew D. Watson
- Diamond
Light Source Ltd, Harwell
Science and Innovation Campus, Didcot OX11 0DE, U.K.
| | - Timur K. Kim
- Diamond
Light Source Ltd, Harwell
Science and Innovation Campus, Didcot OX11 0DE, U.K.
| | - Deepnarayan Biswas
- Diamond
Light Source Ltd, Harwell
Science and Innovation Campus, Didcot OX11 0DE, U.K.
| | - Tien-Lin Lee
- Diamond
Light Source Ltd, Harwell
Science and Innovation Campus, Didcot OX11 0DE, U.K.
| | - Craig M. Polley
- MAX
IV Laboratory, Lund University, P.O. Box 118, Lund 221 00, Sweden
| | - Dina Carbone
- MAX
IV Laboratory, Lund University, P.O. Box 118, Lund 221 00, Sweden
| | - Mats Leandersson
- MAX
IV Laboratory, Lund University, P.O. Box 118, Lund 221 00, Sweden
| | | | - Mohammad Saeed Bahramy
- Department
of Physics and Astronomy, University of
Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Phil D. C. King
- SUPA,
School of Physics and Astronomy, University
of St Andrews, St Andrews KY16 9SS, U.K.
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2
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Wang S, Han Y, Sun S, Wang S, An C, Chen C, Zhang L, Zhou Y, Zhou J, Yang Z. Pressure Induced Nonmonotonic Evolution of Superconductivity in 6R-TaS_{2} with a Natural Bulk Van der Waals Heterostructure. PHYSICAL REVIEW LETTERS 2024; 133:056001. [PMID: 39159112 DOI: 10.1103/physrevlett.133.056001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 06/01/2024] [Accepted: 06/26/2024] [Indexed: 08/21/2024]
Abstract
The natural bulk Van der Waals heterostructure compound 6R-TaS_{2} consists of alternate stacking 1T- and 1H-TaS_{2} monolayers, creating a unique system that incorporates charge-density-wave (CDW) order and superconductivity (SC) in distinct monolayers. Here, after confirming that the 2D nature of the lattice is preserved up to 8 GPa in 6R-TaS_{2}, we documented an unusual evolution of CDW and SC by conducting high-pressure electronic transport measurements. Upon compression, we observe a gradual suppression of CDW within the 1T layers, while the SC exhibits a dome-shaped behavior that terminates at a critical pressure P_{c} around 2.9 GPa. By taking account of the fact that the substantial suppression of SC is concomitant with the complete collapse of CDW order at P_{c}, we argue that the 6R-TaS_{2} behaves like a stack of Josephson junctions and thus the suppressed superconductivity can be attributed to the weakening of Josephson coupling associated with the presence of CDW fluctuations in the 1T layers. Furthermore, the SC reversely enhances above P_{c}, implying the development of emergent superconductivity in the 1T layers after the melting of T-layer CDW orders. These results show that the 6R-TaS_{2} not only provides a promising platform to explore emergent phenomena but also serves as a model system to study the complex interactions between competing electronic states.
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Affiliation(s)
| | | | - Sutao Sun
- National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China
| | | | | | | | | | | | - Jian Zhou
- National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China
| | - Zhaorong Yang
- Anhui Key Laboratory of Low-energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, China
- Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
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3
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Xia W, Wu J, Xia C, Li Z, Yuan J, An C, Liu X, Wang X, Yu N, Zou Z, Liu G, Feng J, Zhang L, Dong Z, Chen B, Yang Z, Yu Z, Chen H, Guo Y. Pressure-Induced Re-Entrant Superconductivity in Transition Metal Dichalcogenide TiSe 2. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2402749. [PMID: 39031112 DOI: 10.1002/smll.202402749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Revised: 06/21/2024] [Indexed: 07/22/2024]
Abstract
Transition metal dichalcogenide TiSe2 exhibits a superconducting dome within a low pressure range of 2-4 GPa, which peaks with the maximal transition temperature Tc of ≈1.8 K. Here it is reported that applying high pressure induces a new superconducting state in TiSe2, which starts at ≈16 GPa with a substantially higher Tc that reaches 5.6 K at ≈21.5 GPa with no sign of decline. Combining high-throughput first-principles structure search, X-ray diffraction, and Raman spectroscopy measurements up to 30 GPa, It is found that TiSe2 undergoes a first-order structural transition from the 1T phase under ambient pressure to a new 4O phase under high pressure. Comparative ab initio calculations reveal that while the conventional phonon-mediated pairing mechanism may account for the superconductivity observed in 1T-TiSe2 under low pressure, the electron-phonon coupling of 4O-TiSe2 is too weak to induce a superconducting state whose transition temperature is as high as 5.6 K under high pressure. The new superconducting state found in pressurized TiSe2 requires further study on its underlying mechanism.
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Affiliation(s)
- Wei Xia
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai, 201210, China
| | - Jiaxuan Wu
- NYU-ECNU Institute of Physics, NYU Shanghai, Shanghai, 200122, China
| | - Chengliang Xia
- NYU-ECNU Institute of Physics, NYU Shanghai, Shanghai, 200122, China
| | - Zhongyang Li
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- Center for High Pressure Science and Technology Advanced Research, Shanghai, 201203, China
| | - Jian Yuan
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Chao An
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, Hefei, 230601, China
| | - Xiangqi Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Xia Wang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Na Yu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Zhiqiang Zou
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Gang Liu
- Center for High Pressure Science and Technology Advanced Research, Shanghai, 201203, China
| | - Jiajia Feng
- Center for High Pressure Science and Technology Advanced Research, Shanghai, 201203, China
| | - Lili Zhang
- Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201204, China
| | - Zhaohui Dong
- Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201204, China
| | - Bin Chen
- Center for High Pressure Science and Technology Advanced Research, Shanghai, 201203, China
| | - Zhaorong Yang
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, 230031, China
| | - Zhenhai Yu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Hanghui Chen
- NYU-ECNU Institute of Physics, NYU Shanghai, Shanghai, 200122, China
- Department of Physics, New York University, New York, 10012, USA
| | - Yanfeng Guo
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai, 201210, China
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4
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Hinlopen RDH, Moulding ON, Broad WR, Buhot J, Bangma F, McCollam A, Ayres J, Sayers CJ, Da Como E, Flicker F, van Wezel J, Friedemann S. Lifshitz transition enabling superconducting dome around a charge-order critical point. SCIENCE ADVANCES 2024; 10:eadl3921. [PMID: 38968362 PMCID: PMC11225790 DOI: 10.1126/sciadv.adl3921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 05/31/2024] [Indexed: 07/07/2024]
Abstract
Superconductivity often emerges as a dome around a quantum critical point (QCP) where long-range order is suppressed to zero temperature, mostly in magnetically ordered materials. However, the emergence of superconductivity at charge-order QCPs remains shrouded in mystery, despite its relevance to high-temperature superconductors and other exotic phases of matter. Here, we present resistance measurements proving that a dome of superconductivity surrounds the putative charge-density-wave QCP in pristine samples of titanium diselenide tuned with hydrostatic pressure. In addition, our quantum oscillation measurements combined with electronic structure calculations show that superconductivity sets in precisely when large electron and hole pockets suddenly appear through an abrupt change of the Fermi surface topology, also known as a Lifshitz transition. Combined with the known repulsive interaction, this suggests that unconventional s± superconductivity is mediated by charge-density-wave fluctuations in titanium diselenide. These results highlight the importance of the electronic ground state and charge fluctuations in enabling unconventional superconductivity.
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Affiliation(s)
- Roemer D. H. Hinlopen
- HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
| | - Owen N. Moulding
- HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
- Institut Néel CNRS/UGA UPR2940, 25 Avenue des Martyrs, Grenoble 38042, France
| | - William R. Broad
- HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
| | - Jonathan Buhot
- HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
- High Field Magnet Laboratory (HFML-EMFL), Radboud University, Toernooiveld 7, Nijmegen 6525 ED, Netherlands
| | - Femke Bangma
- High Field Magnet Laboratory (HFML-EMFL), Radboud University, Toernooiveld 7, Nijmegen 6525 ED, Netherlands
| | - Alix McCollam
- High Field Magnet Laboratory (HFML-EMFL), Radboud University, Toernooiveld 7, Nijmegen 6525 ED, Netherlands
- School of Physics, University College Cork, Cork, Ireland
| | - Jake Ayres
- HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
- High Field Magnet Laboratory (HFML-EMFL), Radboud University, Toernooiveld 7, Nijmegen 6525 ED, Netherlands
| | | | - Enrico Da Como
- Department of Physics, University of Bath, Bath BA2 7AY, UK
| | - Felix Flicker
- HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
- School of Physics and Astronomy, Queen’s Buildings North Building, 5 The Parade, Newport Road, Cardiff CF24 3AA, UK
| | - Jasper van Wezel
- Institute for Theoretical Physics, University of Amsterdam, Science Park 904, Amsterdam, 1098 XH, Netherlands
| | - Sven Friedemann
- HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
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5
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Yang L, Li J, Zhang D, Liu Y, Hu Q. Deviatoric stress-induced metallization, layer reconstruction and collapse of van der Waals bonded zirconium disulfide. Commun Chem 2024; 7:141. [PMID: 38909153 PMCID: PMC11193816 DOI: 10.1038/s42004-024-01223-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 06/12/2024] [Indexed: 06/24/2024] Open
Abstract
In contrast to two-dimensional (2D) monolayer materials, van der Waals layered transition metal dichalcogenides exhibit rich polymorphism, making them promising candidates for novel superconductor, topological insulators and electrochemical catalysts. Here, we highlight the role of hydrostatic pressure on the evolution of electronic and crystal structures of layered ZrS2. Under deviatoric stress, our electrical experiments demonstrate a semiconductor-to-metal transition above 30.2 GPa, while quasi-hydrostatic compression postponed the metallization to 38.9 GPa. Both X-ray diffraction and Raman results reveal structural phase transitions different from those under hydrostatic pressure. Under deviatoric stress, ZrS2 rearranges the original ZrS6 octahedra into ZrS8 cuboids at 5.5 GPa, in which the unique cuboids coordination of Zr atoms is thermodynamically metastable. The structure collapses to a partially disordered phase at 17.4 GPa. These complex phase transitions present the importance of deviatoric stress on the highly tunable electronic properties of ZrS2 with possible implications for optoelectronic devices.
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Affiliation(s)
- Linfei Yang
- Center for High Pressure Science and Technology Advanced Research, 100193, Beijing, China
- School of Materials Science and Engineering, Jingdezhen Ceramic University, Jingdezhen, 333403, Jiangxi, China
| | - Junwei Li
- Center for High Pressure Science and Technology Advanced Research, 100193, Beijing, China
| | - Dongzhou Zhang
- Hawai'i Institute of Geophysics and Planetology, School of Ocean and Earth Science and Technology, University of Hawai'i at Manoa, Honolulu, HI, 96822, USA
| | - Yuegao Liu
- CAS Key Laboratory for Experimental Study under Deep-sea Extreme Conditions, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China
| | - Qingyang Hu
- Center for High Pressure Science and Technology Advanced Research, 100193, Beijing, China.
- Shanghai Advanced Research in Physical Sciences (SHARPS), Shanghai, 201203, China.
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6
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Torbatian Z, Novko D. Plasmon Excitations across the Charge-Density-Wave Transition in Single-Layer TiSe 2. J Phys Chem Lett 2024; 15:6045-6050. [PMID: 38819234 DOI: 10.1021/acs.jpclett.4c01034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2024]
Abstract
1T-TiSe2 is believed to possess a soft electronic mode, i.e., plasmon or exciton, that might be responsible for the exciton condensation and charge-density-wave (CDW) transition. Here, we explore collective electronic excitations in single-layer 1T-TiSe2 by using the ab initio electromagnetic linear response and unveil intricate scattering pathways of the two-dimensional (2D) plasmon mode near the CDW phase. We found the dominant role of plasmon-phonon scattering, which in combination with the CDW gap excitations leads to the anomalous temperature dependence of the plasmon line width across the CDW transition. Below the transition temperature TCDW a strong hybridization between the 2D plasmon and CDW excitations is obtained. These optical features are highly tunable due to temperature-dependent CDW-related modifications of electronic structure and electron-phonon coupling and make CDW-bearing systems potentially interesting for applications in optoelectronics and low-loss plasmonics.
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Affiliation(s)
- Zahra Torbatian
- School of Nano Science, Institute for Research in Fundamental Sciences (IPM), 19395-5531 Tehran, Iran
| | - Dino Novko
- Centre for Advanced Laser Techniques, Institute of Physics, 10000 Zagreb, Croatia
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Spain
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7
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Yan L, Bu K, Li Z, Zhang Z, Xia W, Li M, Li N, Guan J, Liu X, Ning J, Zhang D, Guo Y, Wang X, Yang W. Double Superconducting Dome of Quasi Two-Dimensional TaS 2 in Non-Centrosymmetric van der Waals Heterostructure. NANO LETTERS 2024; 24:6002-6009. [PMID: 38739273 DOI: 10.1021/acs.nanolett.4c00579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2024]
Abstract
Two-dimensional van der Waals heterostructures (2D-vdWHs) based on transition metal dichalcogenides (TMDs) provide unparalleled control over electronic properties. However, the interlayer coupling is challenged by the interfacial misalignment and defects, which hinders a comprehensive understanding of the intertwined electronic orders, especially superconductivity and charge density wave (CDW). Here, by using pressure to regulate the interlayer coupling of non-centrosymmetric 6R-TaS2 vdWHs, we observe an unprecedented phase diagram in TMDs. This phase diagram encompasses successive suppression of the original CDW states from alternating H-layer and T-layer configurations, the emergence and disappearance of a new CDW-like state, and a double superconducting dome induced by different interlayer coupling effects. These results not only illuminate the crucial role of interlayer coupling in shaping the complex phase diagram of TMD systems but also pave a new avenue for the creation of a novel family of bulk heterostructures with customized 2D properties.
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Affiliation(s)
- Limin Yan
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People's Republic of China
- School of Science, Inner Mongolia University of Science and Technology, Baotou 014010, People's Republic of China
- State Key Laboratory of Superhard Materials, Department of Physics, Jilin University, Changchun 130012, People's Republic of China
| | - Kejun Bu
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People's Republic of China
| | - Zhongyang Li
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People's Republic of China
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, People's Republic of China
| | - Zihan Zhang
- State Key Laboratory of Superhard Materials, Department of Physics, Jilin University, Changchun 130012, People's Republic of China
| | - Wei Xia
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, People's Republic of China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai 201210, People's Republic of China
| | - Mingtao Li
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People's Republic of China
| | - Nana Li
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People's Republic of China
| | - Jiayi Guan
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People's Republic of China
- School of Physics, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Xuqiang Liu
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People's Republic of China
| | - Jiahao Ning
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People's Republic of China
| | - Dongzhou Zhang
- GSECARS, University of Chicago, 9700 S. Cass Avenue, Argonne, Illinois 60439, United States
| | - Yanfeng Guo
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, People's Republic of China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai 201210, People's Republic of China
| | - Xin Wang
- State Key Laboratory of Superhard Materials, Department of Physics, Jilin University, Changchun 130012, People's Republic of China
| | - Wenge Yang
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People's Republic of China
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8
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Tang X, Zhou J, Wong NLM, Chai J, Liu Y, Wang S, Song X. Strain-Induced Ferromagnetism in Monolayer T″-Phase VTe 2: Unveiling Magnetic States and Anisotropy for Spintronics Advancement. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:704. [PMID: 38668198 PMCID: PMC11054831 DOI: 10.3390/nano14080704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 04/14/2024] [Accepted: 04/15/2024] [Indexed: 04/29/2024]
Abstract
Two-dimensional (2D) ferromagnets have attracted significant interest for their potential in spintronic device miniaturization, especially since the discovery of ferromagnetic ordering in monolayer materials such as CrI3 and Fe3GeTe2 in 2017. This study presents a detailed investigation into the effects of the Hubbard U parameter, biaxial strain, and structural distortions on the magnetic characteristics of T″-phase VTe2. We demonstrate that setting the Hubbard U to 0 eV provides an accurate representation of the observed structural, magnetic, and electronic features for both bulk and monolayer T″-phase VTe2. The application of strain reveals two distinct ferromagnetic states in the monolayer T″-phase VTe2, each characterized by minor structural differences, but notably different magnetic moments. The T″-1 state, with reduced magnetic moments, emerges under compressive strain, while the T″-2 state, featuring increased magnetic moments, develops under tensile strain. Our analysis also compares the magnetic anisotropy between the T and T″ phases of VTe2, highlighting that the periodic lattice distortion in the T″-phase induces an in-plane anisotropy, which makes it a material with an easy-axis of magnetization. Monte Carlo simulations corroborate our findings, indicating a high Curie temperature of approximately 191 K for the T″-phase VTe2. Our research not only sheds light on the critical aspects of the VTe2 system but also suggests new pathways for enhancing low-dimensional magnetism, contributing to the advancement of spintronics and straintronics.
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Affiliation(s)
- Xiaoting Tang
- Department of Physics, College of Science, Shanghai University, 99 Shangda Road, Shanghai 200444, China;
- Department of Physics, National University of Singapore, Singapore 117542, Singapore
| | - Jun Zhou
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Singapore; (J.Z.); (N.L.M.W.); (J.C.)
| | - Nancy Lai Mun Wong
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Singapore; (J.Z.); (N.L.M.W.); (J.C.)
| | - Jianwei Chai
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Singapore; (J.Z.); (N.L.M.W.); (J.C.)
| | - Yi Liu
- Department of Physics, College of Science, Shanghai University, 99 Shangda Road, Shanghai 200444, China;
- Materials Genome Institute (MGI), Shanghai University, 333 Nanchen Road, Shanghai 200444, China
| | - Shijie Wang
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Singapore; (J.Z.); (N.L.M.W.); (J.C.)
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9
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He D, Zheng Y, Ding D, Ma H, Zhang A, Cheng Y, Zhao W, Jin C. Titanium Self-Intercalation Induced Formation of Orthogonal (1 × 1) Edge/Surface Reconstruction in 1T-TiSe 2: Atomic Scale Dynamics and Mechanistic Study. NANO LETTERS 2024; 24:3835-3841. [PMID: 38498307 DOI: 10.1021/acs.nanolett.4c01040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
Edges and surfaces play indispensable roles in affecting the chemical-physical properties of materials, particularly in two-dimensional transition metal dichalcogenides (TMDCs) with reduced dimensionality. Herein, we report a novel edge/surface structure in multilayer 1T-TiSe2, i.e., the orthogonal (1 × 1) reconstruction, induced by the self-intercalation of Ti atoms into interlayer octahedral sites of the host TiSe2 at elevated temperature. Formation dynamics of the reconstructed edge/surface are captured at the atomic level by in situ scanning transmission electron microscopy (STEM) and further validated by density functional theory (DFT), which enables the proposal of the nucleation mechanism and two growth routes (zigzag and armchair). Via STEM-electron energy loss spectroscopy (STEM-EELS), a chemical shift of 0.6 eV in Ti L3,2 is observed in the reconstructed edge/surface, which is attributed to the change of the coordination number and lattice distortion. The present work provides insights to tailor the atomic/electronic structures and properties of 2D TMDC materials.
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Affiliation(s)
- Daliang He
- State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, P. R. China
- Jihua Laboratory, Foshan, Guangdong 528200, China
| | - Yonghui Zheng
- Key Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal University, Shanghai 200241, China
| | - Degong Ding
- State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, P. R. China
| | - Hao Ma
- School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao, 266580 Shandong, China
| | - Aixinye Zhang
- School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao, 266580 Shandong, China
| | - Yan Cheng
- Key Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal University, Shanghai 200241, China
| | - Wen Zhao
- School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao, 266580 Shandong, China
| | - Chuanhong Jin
- State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, P. R. China
- Jihua Laboratory, Foshan, Guangdong 528200, China
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10
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Paliwal U, Tanwar P, Joshi KB. Structural, electronic and thermoelectric properties of monolayer TiSe 2. J Mol Model 2024; 30:80. [PMID: 38386089 DOI: 10.1007/s00894-024-05865-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 02/03/2024] [Indexed: 02/23/2024]
Abstract
CONTEXT AND RESULTS In this work the first-principles calculations of the structural, electronic and thermoelectric properties of monolayer TiSe2 are presented. The optimized lattice parameter of monolayer TiSe2 shows excellent agreement with the experimental value. The computed band structure and density of states calculations predict metallic nature of monolayer TiSe2 with overlapping of 0.44 eV between the lowest conduction band and top valance band at high symmetry point M. The position of pseudogap formed by Ti-3d orbitals near the Fermi level confirms the mechanical stability of monolayer TiSe2. Due to the influence of positive strain (tensile strain), the Ti-Se bond length increases and the layer height decreases. The applied tensile strain changes the metallic nature of TiSe2 into a semiconductor with opening of bandgap. It has also been observed that the positions of conduction band minima and valance band maxima change with strain. The charge analysis shows that charge transfer from Ti to Se atom increases when tensile strain is applied, while an opposite trend is observed with compression. The computed thermoelectric coefficients i.e. Seeback coefficient, power factor and figure of merit are in good agreement with the experimental data. The temperature dependence of these coefficients is also reported. COMPUTATIONAL METHOD The density functional theory based calculations are reported employing the PBE-GGA ansatz using the plane wave-pseudopotential method embodied in the Quantum ESPRESSO package. The self-consistent field calculations are performed over a dense Monkhorst-Pack net of 12 × 12 × 1 k-points. The energy convergence criteria for the self-consistent field calculation were set to 10-6 Ry/atom with a cutoff energy of 90 Ry. The thermoelectric properties are computed by combining the band structure calculations with the Boltzmann transport equation using Boltztrap2 peckage.
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Affiliation(s)
- Uttam Paliwal
- Department of Physics, Jai Narain Vyas University, Jodhpur, 342011, India.
| | - Pradeep Tanwar
- Department of Physics, Jai Narain Vyas University, Jodhpur, 342011, India
| | - K B Joshi
- Department of Physics, ML Sukhadia University, Udaipur, 313001, India
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11
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Li YC, Zhou J. Predicted multiple charge density wave phases in monolayer 1T-NbO 2. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:185702. [PMID: 38277682 DOI: 10.1088/1361-648x/ad22f9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 01/26/2024] [Indexed: 01/28/2024]
Abstract
Layered transition-metal dichalcogenides, such as NbSe2, have been extensively studied for almost half a century due to their intriguing properties, such as charge density wave (CDW) and superconductivity. Can the layered transition-metal dioxide, such as NbO2, be stable and exhibit CDW, given that it has the same crystal structure and electronic configuration as NbSe2? Here, we use first-principles calculations to predict that 1T-NbO2is possibly stable at high temperatures, but it would undergo two CDW transitions with12×12and13×13periodicities at low temperatures. Both CDW transitions are accompanied by a metal-semiconductor transition. Notably, the13×13CDW phase of NbO2possesses localized magnetic moments and hosts a Mott insulating state. This work offers a fresh outlook on studying CDW and Mott transition in low-dimensional oxide materials.
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Affiliation(s)
- Yi-Chi Li
- National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, People's Republic of China
| | - Jian Zhou
- National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, People's Republic of China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
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12
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Kwon S, Jung H, Lee S, Cho GY, Kong K, Won C, Cheong SW, Yeom HW. Dual Higgs modes entangled into a soliton lattice in CuTe. Nat Commun 2024; 15:984. [PMID: 38302482 PMCID: PMC10834594 DOI: 10.1038/s41467-024-45354-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 01/18/2024] [Indexed: 02/03/2024] Open
Abstract
Recently discovered Higgs particle is a key element in the standard model of elementary particles and its analogue in materials, massive Higgs mode, has elucidated intriguing collective phenomena in a wide range of materials with spontaneous symmetry breaking such as antiferromagnets, cold atoms, superconductors, superfluids, and charge density waves (CDW). As a straightforward extension beyond the standard model, multiple Higgs particles have been considered theoretically but not yet for Higgs modes. Here, we report the real-space observations, which suggest two Higgs modes coupled together with a soliton lattice in a solid. Our scanning tunneling microscopy reveals the 1D CDW state of an anisotropic transition metal monochalcogenide crystal CuTe is composed of two distinct but degenerate CDW structures by the layer inversion symmetry broken. More importantly, the amplitudes of each CDW structure oscillate in an out-of-phase fashion to result in a regular array of alternating domains with repeating phase-shift domain walls. This unusual finding is explained by the extra degeneracy in CDWs within the standard Landau theory of the free energy. The multiple and entangled Higgs modes demonstrate how novel collective modes can emerge in systems with distinct symmetries broken simultaneously.
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Affiliation(s)
- SeongJin Kwon
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, 37673, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Hyunjin Jung
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, 37673, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - SangJin Lee
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, 37673, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Gil Young Cho
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, 37673, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - KiJeong Kong
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, 37673, Korea
| | - ChoongJae Won
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, 37673, Korea
- Laboatory for Pohang Emergent Materials, POSTECH, Pohang, 37673, Korea
- MPPC-CPM, Max Planck POSTECH/Korea Research Initiative, Pohang, 37673, Korea
| | - Sang-Wook Cheong
- Laboatory for Pohang Emergent Materials, POSTECH, Pohang, 37673, Korea
- MPPC-CPM, Max Planck POSTECH/Korea Research Initiative, Pohang, 37673, Korea
- Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Piscataway, NJ, 08854, USA
| | - Han Woong Yeom
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, 37673, Korea.
- Department of Physics, Pohang University of Science and Technology, Pohang, 37673, Korea.
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13
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Pouget JP, Canadell E. Structural approach to charge density waves in low-dimensional systems: electronic instability and chemical bonding. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2024; 87:026501. [PMID: 38052072 DOI: 10.1088/1361-6633/ad124f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 12/05/2023] [Indexed: 12/07/2023]
Abstract
The charge density wave (CDW) instability, usually occurring in low-dimensional metals, has been a topic of interest for longtime. However, some very fundamental aspects of the mechanism remain unclear. Recently, a plethora of new CDW materials, a substantial fraction of which is two-dimensional or even three-dimensional, has been prepared and characterised as bulk and/or single-layers. As a result, the need for revisiting the primary mechanism of the instability, based on the electron-hole instability established more than 50 years ago for quasi-one-dimensional (quasi-1D) conductors, has clearly emerged. In this work, we consider a large number of CDW materials to revisit the main concepts used in understanding the CDW instability, and emphasise the key role of the momentum dependent electron-phonon coupling in linking electronic and structural degrees of freedom. We argue that for quasi-1D systems, earlier weak coupling theories work appropriately and the energy gain due to the CDW and the concomitant periodic lattice distortion (PLD) remains primarily due to a Fermi surface nesting mechanism. However, for materials with higher dimensionality, intermediate and strong coupling regimes are generally at work and the modification of the chemical bonding network by the PLD is at the heart of the instability. We emphasise the need for a microscopic approach blending condensed matter physics concepts and state-of-the-art first-principles calculations with quite fundamental chemical bonding ideas in understanding the CDW phenomenon in these materials.
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Affiliation(s)
- Jean-Paul Pouget
- Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS, 91405 Orsay, France
| | - Enric Canadell
- Institut de Ciencia de Materials de Barcelona, ICMAB-CSIC, Campus de la UAB, 08193 Bellaterra, Spain, and Royal Academy of Sciences and Arts of Barcelona, Chemistry Section, La Rambla 115, 08002 Barcelona, Spain
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14
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Shen X, Heid R, Hott R, Haghighirad AA, Salzmann B, Dos Reis Cantarino M, Monney C, Said AH, Frachet M, Murphy B, Rossnagel K, Rosenkranz S, Weber F. Precursor region with full phonon softening above the charge-density-wave phase transition in 2H-TaSe 2. Nat Commun 2023; 14:7282. [PMID: 37949889 PMCID: PMC10638379 DOI: 10.1038/s41467-023-43094-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 10/31/2023] [Indexed: 11/12/2023] Open
Abstract
Research on charge-density-wave (CDW) ordered transition-metal dichalcogenides continues to unravel new states of quantum matter correlated to the intertwined lattice and electronic degrees of freedom. Here, we report an inelastic x-ray scattering investigation of the lattice dynamics of the canonical CDW compound 2H-TaSe2 complemented by angle-resolved photoemission spectroscopy and density functional perturbation theory. Our results rule out the formation of a central-peak without full phonon softening for the CDW transition in 2H-TaSe2 and provide evidence for a novel precursor region above the CDW transition temperature TCDW, which is characterized by an overdamped phonon mode and not detectable in our photoemission experiments. Thus, 2H-TaSe2 exhibits structural before electronic static order and emphasizes the important lattice contribution to CDW transitions. Our ab-initio calculations explain the interplay of electron-phonon coupling and Fermi surface topology triggering the CDW phase transition and predict that the CDW soft phonon mode promotes emergent superconductivity near the pressure-driven CDW quantum critical point.
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Affiliation(s)
- Xingchen Shen
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
- College of Physics, Chongqing University, Chongqing, 401331, P. R. China
| | - Rolf Heid
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
| | - Roland Hott
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
| | - Amir-Abbas Haghighirad
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
| | - Björn Salzmann
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700, Fribourg, Switzerland
| | - Marli Dos Reis Cantarino
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700, Fribourg, Switzerland
- Instituto de Física, Universidade de São Paulo, São Paulo, São Paulo, 05508-090, Brazil
| | - Claude Monney
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700, Fribourg, Switzerland
| | - Ayman H Said
- Advanced Photon Source, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Mehdi Frachet
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
| | - Bridget Murphy
- Institute of Experimental and Applied Physics and KiNSIS, Kiel University, 24098, Kiel, Germany
- Ruprecht Haensel Laboratory, Kiel University, 24098, Kiel, Germany
| | - Kai Rossnagel
- Institute of Experimental and Applied Physics and KiNSIS, Kiel University, 24098, Kiel, Germany
- Ruprecht Haensel Laboratory, Kiel University, 24098, Kiel, Germany
- Ruprecht Haensel Laboratory, Deutsches Elektronen-Synchrotron DESY, 22607, Hamburg, Germany
| | - Stephan Rosenkranz
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Frank Weber
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany.
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15
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Zheng L, Dang Z, Ding D, Liu Z, Dai Y, Lu J, Fang Z. Electron-Induced Chirality-Selective Routing of Valley Photons via Metallic Nanostructure. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2204908. [PMID: 36877955 DOI: 10.1002/adma.202204908] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 02/13/2023] [Indexed: 06/18/2023]
Abstract
Valleytronics in 2D transition metal dichalcogenides has raised a great impact in nanophotonic information processing and transport as it provides the pseudospin degree of freedom for carrier control. The imbalance of carrier occupation in inequivalent valleys can be achieved by external stimulations such as helical light and electric field. With metasurfaces, it is feasible to separate the valley exciton in real space and momentum space, which is significant for logical nanophotonic circuits. However, the control of valley-separated far-field emission by a single nanostructure is rarely reported, despite the fact that it is crucial for subwavelength research of valley-dependent directional emission. Here, it is demonstrated that the electron beam permits the chirality-selective routing of valley photons in a monolayer WS2 with Au nanostructures. The electron beam can locally excite valley excitons and regulate the coupling between excitons and nanostructures, hence controlling the interference effect of multipolar electric modes in nanostructures. Therefore, the separation degree can be modified by steering the electron beam, exhibiting the capability of subwavelength control of valley separation. This work provides a novel method to create and resolve the variation of valley emission distribution in momentum space, paving the way for the design of future nanophotonic integrated devices.
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Affiliation(s)
- Liheng Zheng
- School of Physics, State Key Lab for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, and Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing, 100871, P. R. China
| | - Zhibo Dang
- School of Physics, State Key Lab for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, and Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing, 100871, P. R. China
| | - Dongdong Ding
- School of Physics, State Key Lab for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, and Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing, 100871, P. R. China
| | - Zhixin Liu
- School of Physics, State Key Lab for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, and Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing, 100871, P. R. China
| | - Yuchen Dai
- School of Physics, State Key Lab for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, and Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing, 100871, P. R. China
| | - Jianming Lu
- School of Physics, State Key Lab for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, and Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing, 100871, P. R. China
| | - Zheyu Fang
- School of Physics, State Key Lab for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, and Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing, 100871, P. R. China
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16
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Zhou J, Wang Z, Wang S, Feng YP, Yang M, Shen L. Coexistence of ferromagnetism and charge density waves in monolayer LaBr 2. NANOSCALE HORIZONS 2023; 8:1054-1061. [PMID: 37395097 DOI: 10.1039/d3nh00150d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Charge density waves (CDWs), a common phenomenon of periodic lattice distortions, often suppress ferromagnetism in two-dimensional (2D) materials, hindering their magnetic applications. Here, we report a novel CDW that generates 2D ferromagnetism instead of suppressing it, through the formation of interstitial anionic electrons as the charge modulation mechanism. Via first-principles calculations and a low-energy effective model, we find that the highly symmetrical monolayer LaBr2 undergoes a 2 × 1 CDW transition to a magnetic semiconducting T' phase. Concurrently, the delocalized 5d1 electrons of La in LaBr2 redistribute and accumulate within the interstitial space in the T' phase, forming anionic electrons, also known as 2D electride or electrene. The strongly localized nature of anionic electrons promotes a Mott insulating state and full spin-polarization, while the overlap of their extended tails yields ferromagnetic direct exchange between them. Such transition introduces a new magnetic form of CDWs, offering promising opportunities for exploring novel fundamental physics and advanced spintronics applications.
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Affiliation(s)
- Jun Zhou
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| | - Zishen Wang
- Department of Physics, National University of Singapore, Singapore 117551, Singapore.
- Centre for Advanced Two-Dimensional Materials (CA2DM), National University of Singapore, Singapore 117546, Singapore
| | - Shijie Wang
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| | - Yuan Ping Feng
- Department of Physics, National University of Singapore, Singapore 117551, Singapore.
- Centre for Advanced Two-Dimensional Materials (CA2DM), National University of Singapore, Singapore 117546, Singapore
| | - Ming Yang
- Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR, China.
| | - Lei Shen
- Department of Mechanical Engineering, National University of Singapore, Singapore 117575, Singapore.
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17
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Hyde PA, Cen J, Cassidy SJ, Rees NH, Holdship P, Smith RI, Zhu B, Scanlon DO, Clarke SJ. Lithium Intercalation into the Excitonic Insulator Candidate Ta 2NiSe 5. Inorg Chem 2023. [PMID: 37466301 PMCID: PMC10394660 DOI: 10.1021/acs.inorgchem.3c01510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
A new reduced phase derived from the excitonic insulator candidate Ta2NiSe5 has been synthesized via the intercalation of lithium. LiTa2NiSe5 crystallizes in the orthorhombic space group Pmnb (no. 62) with lattice parameters a = 3.50247(3) Å, b = 13.4053(4) Å, c = 15.7396(2) Å, and Z = 4, with an increase of the unit cell volume by 5.44(1)% compared with Ta2NiSe5. Significant rearrangement of the Ta-Ni-Se layers is observed, in particular a very significant relative displacement of the layers compared to the parent phase, similar to that which occurs under hydrostatic pressure. Neutron powder diffraction experiments and computational analysis confirm that Li occupies a distorted triangular prismatic site formed by Se atoms of adjacent Ta2NiSe5 layers with an average Li-Se bond length of 2.724(2) Å. Li-NMR experiments show a single Li environment at ambient temperature. Intercalation suppresses the distortion to monoclinic symmetry that occurs in Ta2NiSe5 at 328 K and that is believed to be driven by the formation of an excitonic insulating state. Magnetometry data show that the reduced phase has a smaller net diamagnetic susceptibility than Ta2NiSe5 due to the enhancement of the temperature-independent Pauli paramagnetism caused by the increased density of states at the Fermi level evident also from the calculations, consistent with the injection of electrons during intercalation and formation of a metallic phase.
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Affiliation(s)
- P A Hyde
- Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K
| | - J Cen
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K
- Thomas Young Centre, University College London, Gower Street, London WC1E 6BT, U.K
| | - S J Cassidy
- Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K
| | - N H Rees
- Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K
| | - P Holdship
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, U.K
| | - R I Smith
- Rutherford Appleton Laboratory, ISIS Facility, Harwell Campus, Didcot, Oxon OX11 0QX, U.K
| | - B Zhu
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K
- Thomas Young Centre, University College London, Gower Street, London WC1E 6BT, U.K
| | - D O Scanlon
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K
- Thomas Young Centre, University College London, Gower Street, London WC1E 6BT, U.K
| | - S J Clarke
- Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K
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18
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Jaouen T, Pulkkinen A, Rumo M, Kremer G, Salzmann B, Nicholson CW, Mottas ML, Giannini E, Tricot S, Schieffer P, Hildebrand B, Monney C. Carrier-Density Control of the Quantum-Confined 1T-TiSe_{2} Charge Density Wave. PHYSICAL REVIEW LETTERS 2023; 130:226401. [PMID: 37327408 DOI: 10.1103/physrevlett.130.226401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 05/10/2023] [Indexed: 06/18/2023]
Abstract
Using angle-resolved photoemission spectroscopy, combined with first principle and coupled self-consistent Poisson-Schrödinger calculations, we demonstrate that potassium (K) atoms adsorbed on the low-temperature phase of 1T-TiSe_{2} induce the creation of a two-dimensional electron gas (2DEG) and quantum confinement of its charge-density wave (CDW) at the surface. By further changing the K coverage, we tune the carrier density within the 2DEG that allows us to nullify, at the surface, the electronic energy gain due to exciton condensation in the CDW phase while preserving a long-range structural order. Our Letter constitutes a prime example of a controlled exciton-related many-body quantum state in reduced dimensionality by alkali-metal dosing.
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Affiliation(s)
- T Jaouen
- Univ Rennes, CNRS, (IPR Institut de Physique de Rennes)-UMR 6251, F-35000 Rennes, France
| | - A Pulkkinen
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, CH-1700 Fribourg, Switzerland
- New Technologies Research Centre, University of West Bohemia, CZ-30100 Pilsen, Czech Republic
| | - M Rumo
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, CH-1700 Fribourg, Switzerland
- Haute école d'ingénierie et d'architecture de Fribourg, CH-1700 Fribourg, Switzerland
| | - G Kremer
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, CH-1700 Fribourg, Switzerland
- Institut Jean Lamour, UMR 7198, CNRS-Université de Lorraine, Campus ARTEM, 2 allée André Guinier, BP 50840, 54011 Nancy, France
| | - B Salzmann
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, CH-1700 Fribourg, Switzerland
| | - C W Nicholson
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, CH-1700 Fribourg, Switzerland
- Fritz-Haber-Institute der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - M-L Mottas
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, CH-1700 Fribourg, Switzerland
| | - E Giannini
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - S Tricot
- Univ Rennes, CNRS, (IPR Institut de Physique de Rennes)-UMR 6251, F-35000 Rennes, France
| | - P Schieffer
- Univ Rennes, CNRS, (IPR Institut de Physique de Rennes)-UMR 6251, F-35000 Rennes, France
| | - B Hildebrand
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, CH-1700 Fribourg, Switzerland
| | - C Monney
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, CH-1700 Fribourg, Switzerland
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19
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Duan S, Xia W, Huang C, Wang S, Gu L, Liu H, Xiang D, Qian D, Guo Y, Zhang W. Ultrafast Switching from the Charge Density Wave Phase to a Metastable Metallic State in 1T-TiSe_{2}. PHYSICAL REVIEW LETTERS 2023; 130:226501. [PMID: 37327423 DOI: 10.1103/physrevlett.130.226501] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/28/2023] [Accepted: 05/04/2023] [Indexed: 06/18/2023]
Abstract
The ultrafast electronic structures of the charge density wave material 1T-TiSe_{2} were investigated by high-resolution time- and angle-resolved photoemission spectroscopy. We found that the quasiparticle populations drove ultrafast electronic phase transitions in 1T-TiSe_{2} within 100 fs after photoexcitation, and a metastable metallic state, which was significantly different from the equilibrium normal phase, was evidenced far below the charge density wave transition temperature. Detailed time- and pump-fluence-dependent experiments revealed that the photoinduced metastable metallic state was a result of the halted motion of the atoms through the coherent electron-phonon coupling process, and the lifetime of this state was prolonged to picoseconds with the highest pump fluence used in this study. Ultrafast electronic dynamics were well captured by the time-dependent Ginzburg-Landau model. Our work demonstrates a mechanism for realizing novel electronic states by photoinducing coherent motion of atoms in the lattice.
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Affiliation(s)
- Shaofeng Duan
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Wei Xia
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Chaozhi Huang
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shichong Wang
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Lingxiao Gu
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Haoran Liu
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Dao Xiang
- Key Laboratory for Laser Plasmas (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
- Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Dong Qian
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
- Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Yanfeng Guo
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Wentao Zhang
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
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20
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Meng Q, Yu F, Liu G, Zong J, Tian Q, Wang K, Qiu X, Wang C, Xi X, Zhang Y. Thickness-Dependent Evolutions of Surface Reconstruction and Band Structures in Epitaxial β-In2Se3 Thin Films. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:nano13091533. [PMID: 37177078 PMCID: PMC10180126 DOI: 10.3390/nano13091533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Revised: 04/29/2023] [Accepted: 04/29/2023] [Indexed: 05/15/2023]
Abstract
Ferroelectric materials have received great attention in the field of data storage, benefiting from their exotic transport properties. Among these materials, the two-dimensional (2D) In2Se3 has been of particular interest because of its ability to exhibit both in-plane and out-of-plane ferroelectricity. In this article, we realized the molecular beam epitaxial (MBE) growth of β-In2Se3 films on bilayer graphene (BLG) substrates with precisely controlled thickness. Combining in situ scanning tunneling microscopy (STM) and angle-resolved photoemission spectroscopy (ARPES) measurements, we found that the four-monolayer β-In2Se3 is a semiconductor with a (9 × 1) reconstructed superlattice. In contrast, the monolayer β-In2Se3/BLG heterostructure does not show any surface reconstruction due to the interfacial interaction and moiré superlattice, which instead results in a folding Dirac cone at the center of the Brillouin zone. In addition, we found that the band gap of In2Se3 film decreases after potassium doping on its surface, and the valence band maximum also shifts in momentum after surface potassium doping. The successful growth of high-quality β-In2Se3 thin films would be a new platform for studying the 2D ferroelectric heterostructures and devices. The experimental results on the surface reconstruction and band structures also provide important information on the quantum confinement and interfacial effects in the epitaxial β-In2Se3 films.
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Affiliation(s)
- Qinghao Meng
- National Laboratory of Solid State Microstructure, School of Physics, Nanjing University, Nanjing 210093, China
| | - Fan Yu
- National Laboratory of Solid State Microstructure, School of Physics, Nanjing University, Nanjing 210093, China
| | - Gan Liu
- National Laboratory of Solid State Microstructure, School of Physics, Nanjing University, Nanjing 210093, China
| | - Junyu Zong
- National Laboratory of Solid State Microstructure, School of Physics, Nanjing University, Nanjing 210093, China
| | - Qichao Tian
- National Laboratory of Solid State Microstructure, School of Physics, Nanjing University, Nanjing 210093, China
| | - Kaili Wang
- National Laboratory of Solid State Microstructure, School of Physics, Nanjing University, Nanjing 210093, China
| | - Xiaodong Qiu
- National Laboratory of Solid State Microstructure, School of Physics, Nanjing University, Nanjing 210093, China
| | - Can Wang
- National Laboratory of Solid State Microstructure, School of Physics, Nanjing University, Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- School of Physics and Electronic Sciences, Changsha University of Science and Technology, Changsha 410114, China
| | - Xiaoxiang Xi
- National Laboratory of Solid State Microstructure, School of Physics, Nanjing University, Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Yi Zhang
- National Laboratory of Solid State Microstructure, School of Physics, Nanjing University, Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
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21
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Yan L, Ding C, Li M, Tang R, Chen W, Liu B, Bu K, Huang T, Dai D, Jin X, Yang X, Cheng E, Li N, Zhang Q, Liu F, Liu X, Zhang D, Ma S, Tao Q, Zhu P, Li S, Lü X, Sun J, Wang X, Yang W. Modulating Charge-Density Wave Order and Superconductivity from Two Alternative Stacked Monolayers in a Bulk 4 Hb-TaSe 2 Heterostructure via Pressure. NANO LETTERS 2023; 23:2121-2128. [PMID: 36877932 DOI: 10.1021/acs.nanolett.2c04385] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Two-dimensional (2D) van der Waals heterostructures (VDWHs) containing a charge-density wave (CDW) and superconductivity (SC) have revealed rich tunability in their properties, which provide a new route for optimizing their novel exotic states. The interaction between SC and CDW is critical to its properties; however, understanding this interaction within VDWHs is very limited. A comprehensive in situ study and theoretical calculation on bulk 4Hb-TaSe2 VDWHs consisting of alternately stacking 1T-TaSe2 and 1H-TaSe2 monolayers are investigated under high pressure. Surprisingly, the superconductivity competes with the intralayer and adjacent-layer CDW order in 4Hb-TaSe2, which results in substantially and continually boosted superconductivity under compression. Upon total suppression of the CDW, the superconductivity in the individual layers responds differently to the charge transfer. Our results provide an excellent method to efficiently tune the interplay between SC and CDW in VDWHs and a new avenue for designing materials with tailored properties.
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Affiliation(s)
- Limin Yan
- State Key Laboratory of Superhard Materials, Department of Physics, Jilin University, Changchun 130012, People's Republic of China
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, People's Republic of China
| | - Chi Ding
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Mingtao Li
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, People's Republic of China
| | - Ruilian Tang
- School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022, People's Republic of China
| | - Wan Chen
- State Key Laboratory of Superhard Materials, Department of Physics, Jilin University, Changchun 130012, People's Republic of China
| | - Bingyan Liu
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, People's Republic of China
| | - Kejun Bu
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, People's Republic of China
| | - Tianheng Huang
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Dongzhe Dai
- State Key Laboratory of Surface Physics, Department of Physics, Fudan University Shanghai 200438, People's Republic of China
| | - Xiaobo Jin
- State Key Laboratory of Surface Physics, Department of Physics, Fudan University Shanghai 200438, People's Republic of China
| | - Xiaofan Yang
- State Key Laboratory of Surface Physics, Department of Physics, Fudan University Shanghai 200438, People's Republic of China
| | - Erjian Cheng
- State Key Laboratory of Surface Physics, Department of Physics, Fudan University Shanghai 200438, People's Republic of China
| | - Nana Li
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, People's Republic of China
| | - Qian Zhang
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, People's Republic of China
| | - Fengliang Liu
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, People's Republic of China
| | - Xuqiang Liu
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, People's Republic of China
| | - Dongzhou Zhang
- Hawaii Institute of Geophysics & Planetology, University of Hawaii Manoa, Honolulu, Hawaii 96822, United States
| | - Shuailing Ma
- State Key Laboratory of Superhard Materials, Department of Physics, Jilin University, Changchun 130012, People's Republic of China
| | - Qiang Tao
- State Key Laboratory of Superhard Materials, Department of Physics, Jilin University, Changchun 130012, People's Republic of China
| | - Pinwen Zhu
- State Key Laboratory of Superhard Materials, Department of Physics, Jilin University, Changchun 130012, People's Republic of China
| | - Shiyan Li
- State Key Laboratory of Surface Physics, Department of Physics, Fudan University Shanghai 200438, People's Republic of China
| | - Xujie Lü
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, People's Republic of China
| | - Jian Sun
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Xin Wang
- State Key Laboratory of Superhard Materials, Department of Physics, Jilin University, Changchun 130012, People's Republic of China
| | - Wenge Yang
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, People's Republic of China
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22
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Li YX, Yao ZJ, Yu SL, Li JX. Superconductivity and density-wave fluctuations in an extended triangular Hubbard model: an application to SnSe 2. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 35:045602. [PMID: 36541553 DOI: 10.1088/1361-648x/aca85e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 12/01/2022] [Indexed: 06/17/2023]
Abstract
We employ the fluctuation-exchange approximation to study the relation of superconducting pairing symmetries and density-wave fluctuations based on the extended triangular Hubbard model upon electron doping and interactions, with an possible application to the layered metal dichalcogenide SnSe2. For the case where the interactions between electrons contain only the on-site Hubbard term, the superconducting pairings are mainly mediated by spin fluctuations, and the spin-singlet pairing with thed-wave symmetry robustly dominates in the low and moderate doping levels, and ad-wave to extendeds-wave transition is observed as the electron doping reachesn = 1. When the near-neighbor site Coulomb interactions are also included, the charge fluctuations are enhanced, and the spin-triplet pairings with thep-wave andf-wave symmetries can be realized in the high and low doping levels, respectively.
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Affiliation(s)
- Yun-Xiao Li
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China
| | - Zi-Jian Yao
- Department of Physics, Nanjing Normal University, Nanjing 210023, People's Republic of China
| | - Shun-Li Yu
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Jian-Xin Li
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
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23
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Unveiling the selenium content effect on the properties of TiSe2±α. J SOLID STATE CHEM 2022. [DOI: 10.1016/j.jssc.2022.123768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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24
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Yun SJ, Choi SH, Kim JW, Yoon D, Cho BW, Won YS, Kim JW, Lee J, Kim YI, Kim YM, Kirubasankar B, Kim SM, Kim KK, Lee YH. Internal Thermal Stress-Driven Phase Transformation in Van der Waals Layered Materials. ACS NANO 2022; 16:17033-17040. [PMID: 36173357 DOI: 10.1021/acsnano.2c07150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
High pressure or strain is an effective strategy for generating phase transformations in van der Waals (vdW) layered materials without introducing defects, but this approach remains difficult to perform consistently. We present a scalable and facile method for achieving phase transformation in vdW materials, wherein solid vdW materials are subject to internal thermal stress within a molten metal mantle as it undergoes cooling. This internal thermal stress is principally the product of differential thermal expansion between mantle and core and can be tuned by the mantle material and temperature conditions. We validated this approach by achieving phase transformation of red phosphorus to black phosphorus, and metallic 1T'- to semiconducting 2H-MoTe2 crystals. We further demonstrate quantum electronic phase transformation of suppressed charge density wave in TiSe2 by means of electron-phonon coupling using the same system.
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Affiliation(s)
- Seok Joon Yun
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Soo Ho Choi
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Ji-Won Kim
- Department of Energy Science, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Duhee Yoon
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Byeong Wook Cho
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Yo Seob Won
- Department of Energy Science, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Jae Woo Kim
- Department of Energy Science, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Jina Lee
- Department of Energy Science, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Yong In Kim
- Department of Energy Science, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Young-Min Kim
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | | | - Soo Min Kim
- Department of Chemistry, Sookmyung Women's University, Seoul 14072, Republic of Korea
| | - Ki Kang Kim
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
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25
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Dat VD, Vu TV, Lavrentyev AA, Khyzhun OY, Hieu NN, Tong HD. First-principles study on the structural properties of 2D MXene SnSiGeN 4 and its electronic properties under the effects of strain and an external electric field. RSC Adv 2022; 12:29113-29123. [PMID: 36320756 PMCID: PMC9555058 DOI: 10.1039/d2ra05265b] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 09/24/2022] [Indexed: 12/04/2022] Open
Abstract
The MXene SnSiGeN4 monolayer as a new member of the MoSi2N4 family was proposed for the first time, and its structural and electronic properties were explored by applying first-principles calculations with both PBE and hybrid HSE06 approaches. The layered hexagonal honeycomb structure of SnSiGeN4 was determined to be stable under dynamical effects or at room temperature of 300 K, with a rather high cohesive energy of 7.0 eV. The layered SnSiGeN4 has a Young's modulus of 365.699 N m-1 and a Poisson's ratio of 0.295. The HSE06 approach predicted an indirect band gap of around 2.4 eV for the layered SnSiGeN4. While the major donation from the N-p orbitals to the band structure makes SnSiGeN4's band gap close to those of similar 2D MXenes, the smaller distributions from the other orbitals of Sn, Si, and Ge slightly vary this band gap. The work functions of the GeN and SiN surfaces are 6.367 eV and 5.903 eV, respectively. The band gap of the layered SnSiGeN4 can be easily tuned by strain and an external electric field. A semiconductor-metal transition can occur at certain values of strain, and with an electric field higher than 5 V nm-1. The electron mobility of the layered SnSiGeN4 can reach up to 677.4 cm2 V-1 s-1, which is much higher than the hole mobility of about 52 cm2 V-1 s-1. The mentioned characteristics make the layered SnSiGeN4 a very promising material for use in electronic and photoelectronic devices, and for solar energy conversion.
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Affiliation(s)
- Vo D. Dat
- Laboratory for Computational Physics, Institute for Computational Science and Artificial Intelligence, Van Lang UniversityHo Chi Minh CityVietnam,Faculty of Mechanical – Electrical and Computer Engineering, Van Lang UniversityHo Chi Minh CityVietnam
| | - Tuan V. Vu
- Laboratory for Computational Physics, Institute for Computational Science and Artificial Intelligence, Van Lang UniversityHo Chi Minh CityVietnam,Faculty of Mechanical – Electrical and Computer Engineering, Van Lang UniversityHo Chi Minh CityVietnam
| | - A. A. Lavrentyev
- Department of Electrical Engineering and Electronics, Don State Technical University1 Gagarin Square, 344010 Rostov-on-DonRussian Federation
| | - O. Y. Khyzhun
- Frantsevych Institute for Problems of Materials Science, National Academy of Sciences of Ukraine3 Krzhyzhanovsky StreetUA-03142 KyivUkraine
| | - Nguyen N. Hieu
- Institute of Research and Development, Duy Tan UniversityDa Nang 550000Vietnam,Faculty of Natural Sciences, Duy Tan UniversityDa Nang 550000Vietnam
| | - Hien D. Tong
- Faculty of Engineering, Vietnamese-German UniversityBinh DuongVietnam
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26
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Huber M, Lin Y, Dale N, Sailus R, Tongay S, Kaindl RA, Lanzara A. Revealing the order parameter dynamics of 1T-TiSe[Formula: see text] following optical excitation. Sci Rep 2022; 12:15860. [PMID: 36151110 PMCID: PMC9508156 DOI: 10.1038/s41598-022-19319-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 08/26/2022] [Indexed: 11/09/2022] Open
Abstract
The formation of a charge density wave state is characterized by an order parameter. The way it is established provides unique information on both the role that correlation plays in driving the charge density wave formation and the mechanism behind its formation. Here we use time and angle resolved photoelectron spectroscopy to optically perturb the charge-density phase in 1T-TiSe[Formula: see text] and follow the recovery of its order parameter as a function of energy, momentum and excitation density. Our results reveal that two distinct orders contribute to the gap formation, a CDW order and pseudogap-like order, manifested by an overall robustness to optical excitation. A detailed analysis of the magnitude of the the gap as a function of excitation density and delay time reveals the excitonic long-range nature of the CDW gap and the short-range Jahn-Teller character of the pseudogap order. In contrast to the gap, the intensity of the folded Se[Formula: see text]* band can only give access to the excitonic order. These results provide new information into the the long standing debate on the origin of the gap in TiSe[Formula: see text] and place it in the same context of other quantum materials where a pseudogap phase appears to be a precursor of long-range order.
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Affiliation(s)
- Maximilian Huber
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Yi Lin
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Nicholas Dale
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
- Physics Department, University of California Berkeley, Berkeley, CA 94720 USA
| | - Renee Sailus
- Materials Science and Engineering Department, Arizona State University, Phoenix, AZ 85281 USA
| | - Sefaattin Tongay
- Materials Science and Engineering Department, Arizona State University, Phoenix, AZ 85281 USA
| | - Robert A. Kaindl
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
- Department of Physics and CXFEL Labs, Arizona State University, Phoenix, AZ 85287 USA
| | - Alessandra Lanzara
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
- Physics Department, University of California Berkeley, Berkeley, CA 94720 USA
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27
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Record high Tc element superconductivity achieved in titanium. Nat Commun 2022; 13:5411. [PMID: 36109496 PMCID: PMC9478155 DOI: 10.1038/s41467-022-33077-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 08/29/2022] [Indexed: 11/08/2022] Open
Abstract
It is challenging to search for high Tc superconductivity (SC) in transition metal elements wherein d electrons are usually not favored by conventional BCS theory. Here we report experimental discovery of surprising SC up to 310 GPa with Tc above 20 K in wide pressure range from 108 GPa to 240 GPa in titanium. The maximum Tconset above 26.2 K and zero resistance Tczero of 21 K are record high values hitherto achieved among element superconductors. The Hc2(0) is estimated to be ∼32 Tesla with coherence length 32 Å. The results show strong s-d transfer and d band dominance, indicating correlation driven contributions to high Tc SC in dense titanium. This finding is in sharp contrast to the theoretical predications based on pristine electron-phonon coupling scenario. The study opens a fresh promising avenue for rational design and discovery of high Tc superconductors among simple materials via pressure tuned unconventional mechanism. Superconductivity at megabar pressures has recently attracted interest in the context of hydrides. Here, the authors demonstrate superconductivity up to 26 K at high pressure in elemental titanium, and further suggest that electron correlations contribute to the high Tc.
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28
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Tayran C, Çakmak M. Charge density wave in a SnSe 2 layer on and the effect of surface hydrogenation. Phys Chem Chem Phys 2022; 24:6820-6827. [PMID: 35244640 DOI: 10.1039/d1cp05569k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have carried out an investigation using density functional theory (DFT) of the atomic and electronic structures of SnSe2 layers on the surface and hydrogenation of this surface. We have considered a (2 × 2) SnSe2 superstructure oriented along the diagonal direction of the surface periodicity, for which scanning tunneling microscopy (STM) measurements have recently been reported. In the band structure calculations, while the s-p character surface state originating from each SnSe2 layer is determined, there is an additional half-filled surface state in the fundamental band gap region due to the Sn adatom. At the M̄ point in the Brillouin zone, a charge density wave (CDW) partial gap opening of ∼0.1 eV occurs between these surface states close to the Fermi level. Here, the CDW gap is caused by two reasons; (i) Fermi surface nesting, due to the inequivalent electron pockets at the M̄ point, and (ii) the out of plane weak electron-phonon coupling regime due to the mean-field (MF) theory (2Δ/kBTMF = 3.52). Upon hydrogen adsorption on the surface, we have obtained a β-phase SnSe layer and SeH2 molecule with a bond angle of ∼90°. The hydrogenated surface pushes the surface state associated with the SnSe2 layer into the Si projected bulk band continuum. After SeH2 desorption, the work function drops from 5.20 eV to 4.39 eV.
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Affiliation(s)
- C Tayran
- Department of Physics, Gazi University, Ankara, Turkey.
| | - M Çakmak
- Department of Photonics, Faculty of Applied Sciences, Gazi University, Ankara, Turkey. .,Photonics Application and Research Center, Gazi University, Ankara, Turkey
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29
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Lou R, Fedorov A, Yin Q, Kuibarov A, Tu Z, Gong C, Schwier EF, Büchner B, Lei H, Borisenko S. Charge-Density-Wave-Induced Peak-Dip-Hump Structure and the Multiband Superconductivity in a Kagome Superconductor CsV_{3}Sb_{5}. PHYSICAL REVIEW LETTERS 2022; 128:036402. [PMID: 35119899 DOI: 10.1103/physrevlett.128.036402] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 11/23/2021] [Accepted: 12/23/2021] [Indexed: 05/12/2023]
Abstract
The entanglement of charge density wave (CDW), superconductivity, and topologically nontrivial electronic structure has recently been discovered in the kagome metal AV_{3}Sb_{5} (A=K, Rb, Cs) family. With high-resolution angle-resolved photoemission spectroscopy, we study the electronic properties of CDW and superconductivity in CsV_{3}Sb_{5}. The spectra around K[over ¯] is found to exhibit a peak-dip-hump structure associated with two separate branches of dispersion, demonstrating the isotropic CDW gap opening below E_{F}. The peak-dip-hump line shape is contributed by linearly dispersive Dirac bands in the lower branch and a dispersionless flat band close to E_{F} in the upper branch. The electronic instability via Fermi surface nesting could play a role in determining these CDW-related features. The superconducting gap of ∼0.4 meV is observed on both the electron band around Γ[over ¯] and the flat band around K[over ¯], implying the multiband superconductivity. The finite density of states at E_{F} in the CDW phase is most likely in favor of the emergence of multiband superconductivity, particularly the enhanced density of states associated with the flat band. Our results not only shed light on the controversial origin of the CDW, but also offer insights into the relationship between CDW and superconductivity.
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Affiliation(s)
- Rui Lou
- School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China
- Leibniz Institute for Solid State and Materials Research, IFW Dresden, 01069 Dresden, Germany
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, 12489 Berlin, Germany
| | - Alexander Fedorov
- Leibniz Institute for Solid State and Materials Research, IFW Dresden, 01069 Dresden, Germany
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, 12489 Berlin, Germany
| | - Qiangwei Yin
- Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China
| | - Andrii Kuibarov
- Leibniz Institute for Solid State and Materials Research, IFW Dresden, 01069 Dresden, Germany
| | - Zhijun Tu
- Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China
| | - Chunsheng Gong
- Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China
| | - Eike F Schwier
- Experimentelle Physik VII, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Würzburg-Dresden Cluster of Excellence ct.qmat, Germany
| | - Bernd Büchner
- Leibniz Institute for Solid State and Materials Research, IFW Dresden, 01069 Dresden, Germany
- Institute for Solid State and Materials Physics, TU Dresden, 01062 Dresden, Germany
| | - Hechang Lei
- Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China
| | - Sergey Borisenko
- Leibniz Institute for Solid State and Materials Research, IFW Dresden, 01069 Dresden, Germany
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30
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Ren MQ, Han S, Fan JQ, Wang L, Wang P, Ren W, Peng K, Li S, Wang SZ, Zheng FW, Zhang P, Li F, Ma X, Xue QK, Song CL. Semiconductor-Metal Phase Transition and Emergent Charge Density Waves in 1 T-ZrX 2 (X = Se, Te) at the Two-Dimensional Limit. NANO LETTERS 2022; 22:476-484. [PMID: 34978815 DOI: 10.1021/acs.nanolett.1c04372] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A charge density wave (CDW) is a collective quantum phenomenon in metals and features a wavelike modulation of the conduction electron density. A microscopic understanding and experimental control of this many-body electronic state in atomically thin materials remain hot topics in materials physics. By means of material engineering, we realized a dimensionality and Zr intercalation induced semiconductor-metal phase transition in 1T-ZrX2 (X = Se, Te) ultrathin films, accompanied by a commensurate 2 × 2 CDW order. Furthermore, we observed a CDW energy gap of up to 22 meV around the Fermi level. Fourier-transformed scanning tunneling microscopy and angle-resolved photoemission spectroscopy reveal that 1T-ZrX2 films exhibit the simplest Fermi surface among the known CDW materials in TMDCs, consisting only of a Zr 4d derived elliptical electron conduction band at the corners of the Brillouin zone.
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Affiliation(s)
- Ming-Qiang Ren
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Sha Han
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Jia-Qi Fan
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Li Wang
- Vacuum Interconnected Nanotech Workstation, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, People's Republic of China
| | - Pengdong Wang
- Vacuum Interconnected Nanotech Workstation, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, People's Republic of China
| | - Wei Ren
- Vacuum Interconnected Nanotech Workstation, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, People's Republic of China
| | - Kun Peng
- Vacuum Interconnected Nanotech Workstation, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, People's Republic of China
| | - Shujing Li
- College of Mathematics and Physics, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China
| | - Shu-Ze Wang
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Fa-Wei Zheng
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, People's Republic of China
| | - Ping Zhang
- College of Mathematics and Physics, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China
| | - Fangsen Li
- Vacuum Interconnected Nanotech Workstation, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, People's Republic of China
| | - Xucun Ma
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
- Frontier Science Center for Quantum Information, Beijing 100084, People's Republic of China
| | - Qi-Kun Xue
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
- Frontier Science Center for Quantum Information, Beijing 100084, People's Republic of China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, People's Republic of China
| | - Can-Li Song
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
- Frontier Science Center for Quantum Information, Beijing 100084, People's Republic of China
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31
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Kurzhals P, Kremer G, Jaouen T, Nicholson CW, Heid R, Nagel P, Castellan JP, Ivanov A, Muntwiler M, Rumo M, Salzmann B, Strocov VN, Reznik D, Monney C, Weber F. Electron-momentum dependence of electron-phonon coupling underlies dramatic phonon renormalization in YNi 2B 2C. Nat Commun 2022; 13:228. [PMID: 35017477 PMCID: PMC8752669 DOI: 10.1038/s41467-021-27843-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 12/16/2021] [Indexed: 11/09/2022] Open
Abstract
Electron-phonon coupling, i.e., the scattering of lattice vibrations by electrons and vice versa, is ubiquitous in solids and can lead to emergent ground states such as superconductivity and charge-density wave order. A broad spectral phonon line shape is often interpreted as a marker of strong electron-phonon coupling associated with Fermi surface nesting, i.e., parallel sections of the Fermi surface connected by the phonon momentum. Alternatively broad phonons are known to arise from strong atomic lattice anharmonicity. Here, we show that strong phonon broadening can occur in the absence of both Fermi surface nesting and lattice anharmonicity, if electron-phonon coupling is strongly enhanced for specific values of electron-momentum, k. We use inelastic neutron scattering, soft x-ray angle-resolved photoemission spectroscopy measurements and ab-initio lattice dynamical and electronic band structure calculations to demonstrate this scenario in the highly anisotropic tetragonal electron-phonon superconductor YNi2B2C. This new scenario likely applies to a wide range of compounds.
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Affiliation(s)
- Philipp Kurzhals
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
| | - Geoffroy Kremer
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700, Fribourg, Switzerland
| | - Thomas Jaouen
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700, Fribourg, Switzerland
- Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000, Rennes, France
| | - Christopher W Nicholson
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700, Fribourg, Switzerland
| | - Rolf Heid
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
| | - Peter Nagel
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
| | - John-Paul Castellan
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
- Laboratoire Léon Brillouin (CEA-CNRS), CEA Saclay, F-91911, Gif-sur-Yvette, France
| | - Alexandre Ivanov
- Institut Laue-Langevin, 71 avenue des Martyrs CS 20156, 38042, Grenoble Cedex 9, France
| | - Matthias Muntwiler
- Paul Scherrer Institut, Swiss Light Source, 5232, Villigen PSI, Switzerland
| | - Maxime Rumo
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700, Fribourg, Switzerland
| | - Bjoern Salzmann
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700, Fribourg, Switzerland
| | - Vladimir N Strocov
- Paul Scherrer Institut, Swiss Light Source, 5232, Villigen PSI, Switzerland
| | - Dmitry Reznik
- Department of Physics, University of Colorado at Boulder, Boulder, CO, 80309, USA
- Center for Experiments on Quantum Materials, University of Colorado at Boulder, Boulder, CO, 80309, USA
| | - Claude Monney
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700, Fribourg, Switzerland
| | - Frank Weber
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany.
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32
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Song Y, Meng F, Ying T, Deng J, Wang J, Han X, Zhang Q, Huang Y, Guo JG, Chen X. Spatially Separated Superconductivity and Enhanced Charge-Density-Wave Ordering in an IrTe 2 Nanoflake. J Phys Chem Lett 2021; 12:12180-12186. [PMID: 34918519 DOI: 10.1021/acs.jpclett.1c03302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The interplay among collective electronic states like superconductivity (SC) and charge density wave (CDW) is of significance in transition metal dichalcogenides. To date, a consensus on the relationship between SC and CDW has not been established in IrTe2. Here we use the Au-assisted exfoliation method to cleave IrTe2 down to 10 nm. A striking feature is the concurrence of phase separation in a single piece of nanoflake, i.e., the superconducting (P3̅m1) and CDW (P3̅) phases. In the former area, the dimensional fluctuations suppress the CDW ordering and induce SC at 3.5 K. The CDW area at the phase boundary shows enhanced TCDW at 605 K (TCDW = 280 K in the bulk phase), which is accompanied by a unique wrinkle. Detailed analyses suggest that the strain-induced bond breaking of Te-Te dimers favors the CDW. Our works provide compelling evidence of competition between SC and CDW in IrTe2.
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Affiliation(s)
- Yanpeng Song
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Fanqi Meng
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Tianping Ying
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jun Deng
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Junjie Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xu Han
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology, Beijing 100081, China
| | - Qinghua Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yuan Huang
- Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology, Beijing 100081, China
| | - Jian-Gang Guo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Xiaolong Chen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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33
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Saqib H, Rahman S, Zhao Y, Cazorla C, Errandonea D, Susilo R, Zhuang Y, Huang Y, Chen B, Dai N. Evolution of Structural and Electronic Properties of TiSe 2 under High Pressure. J Phys Chem Lett 2021; 12:9859-9867. [PMID: 34606285 DOI: 10.1021/acs.jpclett.1c02492] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A pressure-induced structural phase transition and its intimate link with the superconducting transition was studied for the first time in TiSe2 up to 40 GPa at room temperature using X-ray diffraction, transport measurement, and first-principles calculations. We demonstrate the occurrence of a first-order structural phase transition at 4 GPa from the standard trigonal structure (S.G.P3̅m1) to another trigonal structure (S-G-P3̅c1). Additionally, at 16 GPa, the P3̅c1 phase spontaneously transforms into a monoclinic C2/m phase, and above 24 GPa, the C2/m phase returns to the initial P3̅m1 phase. Electrical transport results show that metallization occurs above 6 GPa. The charge density wave observed at ambient pressure is suppressed upon compression up to 2 GPa with the emergence of superconductivity at 2.5 GPa, with a critical temperature (Tc) of 2 K. A structural transition accompanies the emergence of superconductivity that persists up to 4 GPa. The results demonstrate that the pressure-induced phase transitions explored by the experiments along with the theoretical predictions may open the door to a new path for searching and controlling the phase diagrams of transition metal dichalcogenides.
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Affiliation(s)
- H Saqib
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
- Shanghai Institute of Technical Physics, Chinese Academy of Science, Shanghai 201800, China
| | - S Rahman
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
- School of Physics and Optoelectronic Engineering, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China
| | - Yongsheng Zhao
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - C Cazorla
- Departament de Física, Universitat Politècnica de Catalunya, Campus Nord B4-B5, Barcelona 08034, Spain
| | - D Errandonea
- Departamento de Física Aplicada-ICMUV, MALTA Consolider Team, Universidad de Valencia, Edificio de Investigación, C/Dr. Moliner 50, Burjassot, Valencia 46100, Spain
| | - Resta Susilo
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Yukai Zhuang
- Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
| | - Yanwei Huang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Bin Chen
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Ning Dai
- Shanghai Institute of Technical Physics, Chinese Academy of Science, Shanghai 201800, China
- School of Physics and Optoelectronic Engineering, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China
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34
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Hu K, Guan LM, Han D, Liu F, Xie SY. From Two-, One-, to Zero-Dimensional Vacancies: A Densification Pattern for a Typcial Transition-Metal Dichalcogenide of TiSe 2. J Phys Chem Lett 2021; 12:9422-9428. [PMID: 34553935 DOI: 10.1021/acs.jpclett.1c02308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In the areas of condensed matter physics, geoscience, material science, and inorganic chemistry, how the crystal structures evolve under an external field such as high-pressure is a fundamental question. By taking TiSe2 as the case, we investigate the phase transformations of the layered transition-metal dichalcogenides (TMDs) under high-pressure. The ambient 6-fold P-3m1 TiSe2 undergoes a transformation into the monoclinic 8-fold coordinated C2/m phase at 15 GPa and then into the hexagonal 9-fold Fe2P-type structure at 34 GPa. The above phase transitions can be unitedly described as the evolution of the vacancies: from a layered structure with two-dimensional (2D) vacancies to the structure with one-dimensional (1D) and zero-dimensional (0D) vacancies. The proposed densification model of TiSe2 reveals the processes how the symmetry breaking phase of spatial chemical bonding restores the symmetry under the isotropic external pressure.
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Affiliation(s)
- Kai Hu
- School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Li-Min Guan
- School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Dong Han
- State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 130033 Changchun, China
| | - Fuyang Liu
- Center for High Pressure Science and Technology Advanced Research, Beijing 100098, China
| | - Sheng-Yi Xie
- School of Physics and Electronics, Hunan University, Changsha 410082, China
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35
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Wang Q, Kong P, Shi W, Pei C, Wen C, Gao L, Zhao Y, Yin Q, Wu Y, Li G, Lei H, Li J, Chen Y, Yan S, Qi Y. Charge Density Wave Orders and Enhanced Superconductivity under Pressure in the Kagome Metal CsV 3 Sb 5. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2102813. [PMID: 34477250 DOI: 10.1002/adma.202102813] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 07/26/2021] [Indexed: 06/13/2023]
Abstract
Superconductivity in topological kagome metals has recently received great research interests. Here, charge density wave (CDW) orders and the evolution of superconductivity under various pressures in CsV3 Sb5 single crystal with V kagome lattice are investigated. By using high-resolution scanning tunneling microscopy/spectroscopy (STM/STS), two CDW orders in CsV3 Sb5 are observed which correspond to 4a × 1a and 2a × 2a superlattices. By applying pressure, the superconducting transition temperature Tc is significantly enhanced and reaches a maximum value of 8.2 K at around 1 GPa. Accordingly, CDW state is gradually declined as increasing the pressure, which indicates the competing interplay between CDW and superconducting state in this material. The broad superconducting transitions around 0.4-0.8 GPa can be related to the strong competition relation among two CDW states and superconductivity. These results demonstrate that CsV3 Sb5 is a new platform for exploring the interplay between superconductivity and CDW in topological kagome metals.
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Affiliation(s)
- Qi Wang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai, 201210, China
| | - Pengfei Kong
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Wujun Shi
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- Center for Transformative Science, ShanghaiTech University, Shanghai, 201210, China
- Shanghai High Repetition Rate XFEL and Extreme Light Facility (SHINE), ShanghaiTech University, Shanghai, 201210, China
| | - Cuiying Pei
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Chenhaoping Wen
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Lingling Gao
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yi Zhao
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Qiangwei Yin
- Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices, Renmin University of China, Beijing, 100872, China
| | - Yueshen Wu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Gang Li
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai, 201210, China
| | - Hechang Lei
- Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices, Renmin University of China, Beijing, 100872, China
| | - Jun Li
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai, 201210, China
| | - Yulin Chen
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai, 201210, China
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU, UK
| | - Shichao Yan
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai, 201210, China
| | - Yanpeng Qi
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
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36
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Li S, Zhang Z, Xu C, Liu Z, Chen X, Bian Q, Gedeon H, Shao Z, Liu L, Liu Z, Kang N, Cheng HM, Ren W, Pan M. Magnetic Doping Induced Superconductivity-to-Incommensurate Density Waves Transition in a 2D Ultrathin Cr-Doped Mo 2C Crystal. ACS NANO 2021; 15:14938-14946. [PMID: 34469117 DOI: 10.1021/acsnano.1c05133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In the vicinity of a competing electronic order, superconductivity emerges within a superconducting dome in the phase diagram, which has been demonstrated in unconventional superconductors and transition-metal dichalcogenides (TMDs), suggesting a scenario where fluctuations or a partial melting of a parent order are essential for inducing superconductivity. Here, we present a contrary example, the two-dimensional (2D) superconductivity in transition-metal carbide can be readily turned into charge density wave (CDW) phases via dilute magnetic doping. Low temperature scanning tunneling microscopy/spectroscopy (STM/STS), transport measurements, and density functional theory (DFT) calculations were employed to investigate Cr-doped superconducting Mo2C crystals in the 2D limit. With ultralow Cr doping (2.7 atom %), the superconductivity of Mo2C is heavily suppressed. Strikingly, an incommensurate density wave (IDW) and a related partially opened gap are observed at a temperature above the superconducting regime. The wave vector of IDW agrees well with the calculated Fermi surface nesting vectors. By further increasing the Cr doping level to 9.4 atom %, a stronger IDW with a smaller periodicity and a larger partial gap appear concurrently. The resistance anomaly implies the onset of the CDW phase. Spatial-resolved and temperature-dependent spectroscopy reveals that such CDW phases exist only in a nonsuperconducting regime and could form long-range orders uniformly. The results provide the understanding for the interplay between charge ordered states and superconductivity in 2D transition-metal carbide.
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Affiliation(s)
- Shaojian Li
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | - Zongyuan Zhang
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
- Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, P. R. China
| | - Chuan Xu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, P. R. China
| | - Zhen Liu
- Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871, P. R. China
| | - Xiaorui Chen
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710119, China
| | - Qi Bian
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | - Habakubaho Gedeon
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | - Zhibin Shao
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710119, China
| | - Lijun Liu
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | - Zhibo Liu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, P. R. China
| | - Ning Kang
- Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871, P. R. China
| | - Hui-Ming Cheng
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, P. R. China
- School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, P. R. China
- Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute (TBSI), Tsinghua University, Shenzhen 518055, P. R. China
| | - Wencai Ren
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, P. R. China
- School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, P. R. China
| | - Minghu Pan
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710119, China
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37
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Coexistence of resistance oscillations and the anomalous metal phase in a lithium intercalated TiSe 2 superconductor. Nat Commun 2021; 12:5342. [PMID: 34504094 PMCID: PMC8429654 DOI: 10.1038/s41467-021-25671-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 08/22/2021] [Indexed: 11/24/2022] Open
Abstract
Superconductivity and charge density wave (CDW) appear in the phase diagram of a variety of materials including the high-Tc cuprate family and many transition metal dichalcogenides (TMDs). Their interplay may give rise to exotic quantum phenomena. Here, we show that superconducting arrays can spontaneously form in TiSe2–a TMD with coexisting superconductivity and CDW—after lithium ion intercalation. We induce a superconducting dome in the phase diagram of LixTiSe2 by using the ionic solid-state gating technique. Around optimal doping, we observe magnetoresistance oscillations, indicating the emergence of periodically arranged domains. In the same temperature, magnetic field and carrier density regime where the resistance oscillations occur, we observe signatures for the anomalous metal—a state with a resistance plateau across a wide temperature range below the superconducting transition. Our study not only sheds further insight into the mechanism for the periodic electronic structure, but also reveals the interplay between the anomalous metal and superconducting fluctuations. The interplay between superconductivity and charge density wave (CDW) gives rise to exotic quantum phenomena. Here, the authors observe magnetoresistance oscillations and an anomalous metal state due to the coexistence of superconductivity and CDW in lithium intercalated TiSe2.
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38
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Lin T, Wang X, Chen X, Liu X, Luo X, Li X, Jing X, Dong Q, Liu B, Liu H, Li Q, Zhu X, Liu B. Retainable Superconductivity and Structural Transition in 1T-TaSe 2 Under High Pressure. Inorg Chem 2021; 60:11385-11393. [PMID: 34289304 DOI: 10.1021/acs.inorgchem.1c01378] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
As a prominent platform possessing the properties of superconductivity (SC) and charge density wave (CDW), transition-metal dichalcogenides (TMDCs) have attracted considerable attention for a long time. Moreover, extensive efforts have been devoted for exploring the SC and/or the interplay between SC and CDW in TMDCs in the past few decades. Here, we systematically investigate the electronic properties and structural evolution of 1T-TaSe2 under pressure. With increasing pressure, pressure-induced superconductivity is observed at ∼2.6 GPa. The superconductive transition temperature (Tc) increases with the suppression of the CDW state to the maximum value of ∼5.1 K at 21.8 GPa and then decreases monotonously up to the highest pressure of 57.8 GPa. 1T-TaSe2 transforms into a monoclinic C2/m structure above 19 GPa. The monoclinic phase coexists with the original phase as the pressure is released under ambient conditions and the retainable superconductivity with Tc = 2.9 K is observed in the released sample. We suggest that the retained superconductivity can be ascribed to the retention of the superconductive high-pressure monoclinic phase in the released sample. Our findings demonstrate that both the structure and CDW order are related to the superconductivity of TaSe2.
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Affiliation(s)
- Tao Lin
- State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, People's Republic of China
| | - Xiaojun Wang
- Laboratory of High Pressure Physics and Material Science, School of Physics and Physical Engineering, Qufu Normal University, Qufu 273100, People's Republic of China
| | - Xin Chen
- Laboratory of High Pressure Physics and Material Science, School of Physics and Physical Engineering, Qufu Normal University, Qufu 273100, People's Republic of China
| | - Xiaobing Liu
- Laboratory of High Pressure Physics and Material Science, School of Physics and Physical Engineering, Qufu Normal University, Qufu 273100, People's Republic of China
| | - Xuan Luo
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
| | - Xue Li
- State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, People's Republic of China
| | - Xiaoling Jing
- State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, People's Republic of China
| | - Qing Dong
- State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, People's Republic of China
| | - Bo Liu
- State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, People's Republic of China
| | - Hanyu Liu
- State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, People's Republic of China
| | - Quanjun Li
- State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, People's Republic of China
| | - Xuebin Zhu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
| | - Bingbing Liu
- State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, People's Republic of China
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Chen KY, Wang NN, Yin QW, Gu YH, Jiang K, Tu ZJ, Gong CS, Uwatoko Y, Sun JP, Lei HC, Hu JP, Cheng JG. Double Superconducting Dome and Triple Enhancement of T_{c} in the Kagome Superconductor CsV_{3}Sb_{5} under High Pressure. PHYSICAL REVIEW LETTERS 2021; 126:247001. [PMID: 34213920 DOI: 10.1103/physrevlett.126.247001] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 05/18/2021] [Indexed: 05/12/2023]
Abstract
CsV_{3}Sb_{5} is a newly discovered Z_{2} topological kagome metal showing the coexistence of a charge-density-wave (CDW)-like order at T^{*}=94 K and superconductivity (SC) at T_{c}=2.5 K at ambient pressure. Here, we study the interplay between CDW and SC in CsV_{3}Sb_{5} via measurements of resistivity, dc and ac magnetic susceptibility under various pressures up to 6.6 GPa. We find that the CDW transition decreases with pressure and experience a subtle modification at P_{c1}≈0.6-0.9 GPa before it vanishes completely at P_{c2}≈2 GPa. Correspondingly, T_{c}(P) displays an unusual M-shaped double dome with two maxima around P_{c1} and P_{c2}, respectively, leading to a tripled enhancement of T_{c} to about 8 K at 2 GPa. The obtained temperature-pressure phase diagram resembles those of unconventional superconductors, illustrating an intimated competition between CDW-like order and SC. The competition is found to be particularly strong for the intermediate pressure range P_{c1}≤P≤P_{c2} as evidenced by the broad superconducting transition and reduced superconducting volume fraction. The modification of CDW order around P_{c1} has been discussed based on the band structure calculations. This work not only demonstrates the potential to raise T_{c} of the V-based kagome superconductors, but also offers more insights into the rich physics related to the electron correlations in this novel family of topological kagome metals.
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Affiliation(s)
- K Y Chen
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - N N Wang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Q W Yin
- Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China
| | - Y H Gu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - K Jiang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Z J Tu
- Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China
| | - C S Gong
- Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China
| | - Y Uwatoko
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - J P Sun
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - H C Lei
- Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China
| | - J P Hu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - J-G Cheng
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
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40
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Yu FH, Ma DH, Zhuo WZ, Liu SQ, Wen XK, Lei B, Ying JJ, Chen XH. Unusual competition of superconductivity and charge-density-wave state in a compressed topological kagome metal. Nat Commun 2021; 12:3645. [PMID: 34112779 PMCID: PMC8192749 DOI: 10.1038/s41467-021-23928-w] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 05/26/2021] [Indexed: 12/01/2022] Open
Abstract
Understanding the competition between superconductivity and other ordered states (such as antiferromagnetic or charge-density-wave (CDW) state) is a central issue in condensed matter physics. The recently discovered layered kagome metal AV3Sb5 (A = K, Rb, and Cs) provides us a new playground to study the interplay of superconductivity and CDW state by involving nontrivial topology of band structures. Here, we conduct high-pressure electrical transport and magnetic susceptibility measurements to study CsV3Sb5 with the highest Tc of 2.7 K in AV3Sb5 family. While the CDW transition is monotonically suppressed by pressure, superconductivity is enhanced with increasing pressure up to P1 ≈ 0.7 GPa, then an unexpected suppression on superconductivity happens until pressure around 1.1 GPa, after that, Tc is enhanced with increasing pressure again. The CDW is completely suppressed at a critical pressure P2 ≈ 2 GPa together with a maximum Tc of about 8 K. In contrast to a common dome-like behavior, the pressure-dependent Tc shows an unexpected double-peak behavior. The unusual suppression of Tc at P1 is concomitant with the rapidly damping of quantum oscillations, sudden enhancement of the residual resistivity and rapid decrease of magnetoresistance. Our discoveries indicate an unusual competition between superconductivity and CDW state in pressurized kagome lattice.
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Affiliation(s)
- F H Yu
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui, China
| | - D H Ma
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui, China
| | - W Z Zhuo
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui, China
| | - S Q Liu
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui, China
| | - X K Wen
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui, China
| | - B Lei
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui, China
| | - J J Ying
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui, China.
| | - X H Chen
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui, China.
- CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei, Anhui, China.
- Collaborative Innovation Center of Advanced Microstructures, Nanjing, PR China.
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41
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Li S, Dong Q, Feng J, Wang Y, Hou M, Deng W, Susilo RA, Li N, Dong H, Wan S, Gao C, Chen B. Evolution of Structural and Electronic Properties in NbTe 2 under High Pressure. Inorg Chem 2021; 60:7857-7864. [PMID: 34015921 DOI: 10.1021/acs.inorgchem.1c00360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Transition metal dichalcogenides (TMDs) have attracted wide attention due to their quasi-two-dimensional layered structure and exotic properties. Plenty of efforts have been done to modulate the interlayer stacking manner for novel states. However, as an equally important element in shaping the unique properties of TMDs, the effect of intralayer interaction is rarely revealed. Here, we report a particular case of pressure-tuned re-arrangement of intralayer atoms in distorted 1T-NbTe2, which was demonstrated to be a new type of structural phase transition in TMDs. The structural transition occurs in the pressure range of 16-20 GPa, resulting in a transformation of Nb atomic arrangement from the trimeric to dimeric structure, accompanied by a dramatic collapse of unit cell volume and lattice parameters. Simultaneously, a charge density wave (CDW) was also found to collapse during the phase transition. The strong increase in the critical fluctuations of CDW induces a significant decline in the electronic correlation and a change of charge carrier type from hole to electron in NbTe2. Our finding reveals a new mechanism of structure evolution and expands the field of pressure-induced phase transition.
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Affiliation(s)
- Shujia Li
- State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China.,Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Qing Dong
- State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China
| | - Jiajia Feng
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Yanju Wang
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Mingqiang Hou
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China.,Institute of Meteoritics, Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, New Mexico 87131, United Sstates
| | - Wen Deng
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Resta A Susilo
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Nana Li
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Hongliang Dong
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Shun Wan
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Chunxiao Gao
- State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China
| | - Bin Chen
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
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42
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Lee JM, Oshikawa M, Cho GY. Non-Fermi Liquids in Conducting Two-Dimensional Networks. PHYSICAL REVIEW LETTERS 2021; 126:186601. [PMID: 34018806 DOI: 10.1103/physrevlett.126.186601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 04/01/2021] [Indexed: 06/12/2023]
Abstract
We explore the physics of novel fermion liquids emerging from conducting networks, where 1D metallic wires form a periodic 2D superstructure. Such structure naturally appears in marginally twisted bilayer graphenes, moire transition metal dichalcogenides, and also in some charge-density wave materials. For these network systems, we theoretically show that a remarkably wide variety of new non-Fermi liquids emerge and that these non-Fermi liquids can be classified by the characteristics of the junctions in networks. Using this, we calculate the electric conductivity of the non-Fermi liquids as a function of temperature, which show markedly different scaling behaviors than a regular 2D Fermi liquid.
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Affiliation(s)
- Jongjun M Lee
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
| | - Masaki Oshikawa
- Institute for Solid State Physics, The University of Tokyo, Kashiwa 277-8581, Japan
- Kavli Institute for the Physics and Mathematics of the Universe, Kashiwa 277-8583, Japan
- Trans-scale Quantum Science Institute, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Gil Young Cho
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
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43
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Zhang W, Fang Y, Zhang Z, Tian F, Huang Y, Wang X, Huang X, Huang F, Cui T. A New Superconducting 3R-WS 2 Phase at High Pressure. J Phys Chem Lett 2021; 12:3321-3327. [PMID: 33769817 DOI: 10.1021/acs.jpclett.1c00312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
High-pressure investigation has been shown to be of paramount significance for changing the conventional lattice or bringing fascinating properties, especially inducing superconducting phases. Here we studied the application of pressure to the recently synthesized 2M-WS2 with the record Tc (8.8 K) among transition metal dichalcogenides (TMDs) at ambient pressure by electrical resistance investigations, synchrotron X-ray studies, and theoretical calculations. Tc in the initial 2M-WS2 dropped from the maximum to become undetected, accompanied by a phase transition into a semiconductor, 3R-WS2, at 15 GPa. The successive metallization and superconducting transitions in 3R-WS2 were observed at 48.8 GPa with Tc ≈ 2.5 K. This is the first experimental case in which superconductivity has been realized in the 3R phase among TMDs. We propose that the degradation of superconductivity in 2M-WS2 and the reemergence of superconductivity in 3R-WS2 are mainly attributable to changes in the density of states near the Fermi surface driven by the interlayer coupling.
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Affiliation(s)
- Wenting Zhang
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China
| | - Yuqiang Fang
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Zihan Zhang
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China
| | - Fubo Tian
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China
| | - Yanping Huang
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China
| | - Xin Wang
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China
| | - Xiaoli Huang
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China
| | - Fuqiang Huang
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Tian Cui
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China
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44
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Li Z, Wu Q, Wu C. Surface/Interface Chemistry Engineering of Correlated-Electron Materials: From Conducting Solids, Phase Transitions to External-Field Response. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2002807. [PMID: 33643796 PMCID: PMC7887576 DOI: 10.1002/advs.202002807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 09/25/2020] [Indexed: 06/12/2023]
Abstract
Correlated electronic materials (CEMs) with strong electron-electron interactions are often associated with exotic properties, such as metal-insulator transition (MIT), charge density wave (CDW), superconductivity, and magnetoresistance (MR), which are fundamental to next generation condensed matter research and electronic devices. When the dimension of CEMs decreases, exposing extremely high specific surface area and enhancing electronic correlation, the surface states are equally important to the bulk phase. Therefore, surface/interface chemical interactions provide an alternative route to regulate the intrinsic properties of low-dimensional CEMs. Here, recent achievements in surface/interface chemistry engineering of low-dimensional CEMs are reviewed, using surface modification, molecule-solid interaction, and interface electronic coupling, toward modulation of conducting solids, phase transitions including MIT, CDW, superconductivity, and magnetism transition, as well as external-field response. Surface/interface chemistry engineering provides a promising strategy for exploring novel properties and functional applications in low-dimensional CEMs. Finally, the current challenge and outlook of the surface/interface engineering are also pointed out for future research development.
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Affiliation(s)
- Zejun Li
- Hefei National Laboratory for Physical Sciences at the MicroscaleCAS center for Excellence in Nanoscienceand CAS Key Laboratory of Mechanical Behavior and Design of MaterialsUniversity of Science and Technology of ChinaHefeiAnhui230026PR China
| | - Qiran Wu
- Hefei National Laboratory for Physical Sciences at the MicroscaleCAS center for Excellence in Nanoscienceand CAS Key Laboratory of Mechanical Behavior and Design of MaterialsUniversity of Science and Technology of ChinaHefeiAnhui230026PR China
| | - Changzheng Wu
- Hefei National Laboratory for Physical Sciences at the MicroscaleCAS center for Excellence in Nanoscienceand CAS Key Laboratory of Mechanical Behavior and Design of MaterialsUniversity of Science and Technology of ChinaHefeiAnhui230026PR China
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45
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Zhang L, Tang Y, Khan AR, Hasan MM, Wang P, Yan H, Yildirim T, Torres JF, Neupane GP, Zhang Y, Li Q, Lu Y. 2D Materials and Heterostructures at Extreme Pressure. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:2002697. [PMID: 33344136 PMCID: PMC7740103 DOI: 10.1002/advs.202002697] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/03/2020] [Indexed: 06/02/2023]
Abstract
2D materials possess wide-tuning properties ranging from semiconducting and metallization to superconducting, etc., which are determined by their structure, empowering them to be appealing in optoelectronic and photovoltaic applications. Pressure is an effective and clean tool that allows modifications of the electronic structure, crystal structure, morphologies, and compositions of 2D materials through van der Waals (vdW) interaction engineering. This enables an insightful understanding of the variable vdW interaction induced structural changes, structure-property relations as well as contributes to the versatile implications of 2D materials. Here, the recent progress of high-pressure research toward 2D materials and heterostructures, involving graphene, boron nitride, transition metal dichalcogenides, 2D perovskites, black phosphorene, MXene, and covalent-organic frameworks, using diamond anvil cell is summarized. A detailed analysis of pressurized structure, phonon dynamics, superconducting, metallization, doping together with optical property is performed. Further, the pressure-induced optimized properties and potential applications as well as the vision of engineering the vdW interactions in heterostructures are highlighted. Finally, conclusions and outlook are presented on the way forward.
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Affiliation(s)
- Linglong Zhang
- Institute of Microscale OptoelectronicsCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060China
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
| | - Yilin Tang
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
| | - Ahmed Raza Khan
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
| | - Md Mehedi Hasan
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
| | - Ping Wang
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
| | - Han Yan
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
| | - Tanju Yildirim
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
| | - Juan Felipe Torres
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
| | - Guru Prakash Neupane
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
| | - Yupeng Zhang
- Institute of Microscale OptoelectronicsCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060China
| | - Quan Li
- International Center for Computational Methods and SoftwareCollege of PhysicsJilin UniversityChangchun130012China
| | - Yuerui Lu
- Research School of Electrical, Energy and Materials EngineeringCollege of Engineering and Computer ScienceThe Australian National UniversityCanberraACT2601Australia
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46
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Zhang J, Phelan D, Botana AS, Chen YS, Zheng H, Krogstad M, Wang SG, Qiu Y, Rodriguez-Rivera JA, Osborn R, Rosenkranz S, Norman MR, Mitchell JF. Intertwined density waves in a metallic nickelate. Nat Commun 2020; 11:6003. [PMID: 33243978 PMCID: PMC7691989 DOI: 10.1038/s41467-020-19836-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 11/03/2020] [Indexed: 11/09/2022] Open
Abstract
Nickelates are a rich class of materials, ranging from insulating magnets to superconductors. But for stoichiometric materials, insulating behavior is the norm, as for most late transition metal oxides. Notable exceptions are the 3D perovskite LaNiO3, an unconventional paramagnetic metal, and the layered Ruddlesden-Popper phases R4Ni3O10, (R = La, Pr, Nd). The latter are particularly intriguing because they exhibit an unusual metal-to-metal transition. Here, we demonstrate that this transition results from an incommensurate density wave with both charge and magnetic character that lies closer in its behavior to the metallic density wave seen in chromium metal than the insulating stripes typically found in single-layer nickelates like La2-xSrxNiO4. We identify these intertwined density waves as being Fermi surface-driven, revealing a novel ordering mechanism in this nickelate that reflects a coupling among charge, spin, and lattice degrees of freedom that differs not only from the single-layer materials, but from the 3D perovskites as well. Layered Ruddlesden-Popper structure nickelates R4Ni3O10 (R = La,Pr) show an unusual metal-to-metal transition, but its origin has remained elusive for more than two decades. Here, the authors show that this transition results from intertwined density waves that arise from a coupling between charge and spin degrees of freedom
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Affiliation(s)
- Junjie Zhang
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, United States. .,Institute of Crystal Materials, State Key Laboratory of Crystal Materials, Shandong University, 250100, Jinan, Shandong, China.
| | - D Phelan
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, United States
| | - A S Botana
- Department of Physics, Arizona State University, Tempe, AZ, 85287, United States
| | - Yu-Sheng Chen
- ChemMatCARS, The University of Chicago, Lemont, IL, 60439, United States
| | - Hong Zheng
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, United States
| | - M Krogstad
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, United States
| | - Suyin Grass Wang
- ChemMatCARS, The University of Chicago, Lemont, IL, 60439, United States
| | - Yiming Qiu
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899, United States
| | - J A Rodriguez-Rivera
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899, United States.,Department of Materials Science, University of Maryland, College Park, MD, 20742, United States
| | - R Osborn
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, United States
| | - S Rosenkranz
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, United States
| | - M R Norman
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, United States
| | - J F Mitchell
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, United States.
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47
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Wang Y, Hamann DM, Cordova DLM, Chen J, Wang B, Shen L, Cai Z, Shi H, Karapetrova E, Aravind I, Shi L, Johnson DC, Cronin SB. Enhanced Low-Temperature Thermoelectric Performance in (PbSe) 1+δ(VSe 2) 1 Heterostructures due to Highly Correlated Electrons in Charge Density Waves. NANO LETTERS 2020; 20:8008-8014. [PMID: 33095023 DOI: 10.1021/acs.nanolett.0c02882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We explore the effect of charge density wave (CDW) on the in-plane thermoelectric transport properties of (PbSe)1+δ(VSe2)1 and (PbSe)1+δ(VSe2)2 heterostructures. In (PbSe)1+δ(VSe2)1 we observe an abrupt 86% increase in the Seebeck coefficient, 245% increase in the power factor, and a slight decrease in resistivity over the CDW transition. This behavior is not observed in (PbSe)1+δ(VSe2)2 and is rather unusual compared to the general trend observed in other materials. The abrupt transition causes a deviation from the Mott relationship through correlated electron states. Raman spectra of the (PbSe)1+δ(VSe2)1 material show the emergence of additional peaks below the CDW transition temperature associated with VSe2 material. Temperature-dependent in-plane X-ray diffraction (XRD) spectra show a change in the in-plane thermal expansion of VSe2 in (PbSe)1+δ(VSe2)1 due to lattice distortion. The increase in the power factor and decrease in the resistivity due to CDW suggest a potential mechanism for enhancing the thermoelectric performance at the low temperature region.
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Affiliation(s)
| | - Danielle M Hamann
- Department of Chemistry, University of Oregon, Eugene, Oregon 97403-1253, United States
| | - Dmitri Leo M Cordova
- Department of Chemistry, University of Oregon, Eugene, Oregon 97403-1253, United States
| | | | | | | | | | | | - Evguenia Karapetrova
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | | | - Li Shi
- Department of Mechanical Engineering and Texas Materials Institute, University of Texas at Austin, Austin, Texas 78712, United States
| | - David C Johnson
- Department of Chemistry, University of Oregon, Eugene, Oregon 97403-1253, United States
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48
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El Baggari I, Sivadas N, Stiehl GM, Waelder J, Ralph DC, Fennie CJ, Kourkoutis LF. Direct Visualization of Trimerized States in 1T^{'}-TaTe_{2}. PHYSICAL REVIEW LETTERS 2020; 125:165302. [PMID: 33124841 DOI: 10.1103/physrevlett.125.165302] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 06/03/2020] [Accepted: 08/26/2020] [Indexed: 06/11/2023]
Abstract
Transition-metal dichalcogenides containing tellurium anions show remarkable charge-lattice modulated structures and prominent interlayer character. Using cryogenic scanning transmission electron microscopy (STEM), we map the atomic-scale structures of the high temperature (HT) and low temperature (LT) modulated phases in 1T^{'}-TaTe_{2}. At HT, we directly show in-plane metal distortions which form trimerized clusters and staggered, three-layer stacking. In the LT phase at 93 K, we visualize an additional trimerization of Ta sites and subtle distortions of Te sites by extracting structural information from contrast modulations in plan-view STEM data. Coupled with density functional theory calculations and image simulations, this approach opens the door for atomic-scale visualizations of low temperature phase transitions and complex displacements in a variety of layered systems.
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Affiliation(s)
- Ismail El Baggari
- Department of Physics, Cornell University, Ithaca, New York 14853, USA
| | - Nikhil Sivadas
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA
| | - Gregory M Stiehl
- Department of Physics, Cornell University, Ithaca, New York 14853, USA
| | - Jacob Waelder
- Platform for the Accelerated Realization, Analysis and Discovery of Interface Materials (PARADIM), Cornell University, Ithaca, New York 14853, USA
| | - Daniel C Ralph
- Department of Physics, Cornell University, Ithaca, New York 14853, USA
- Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, New York 14853, USA
| | - Craig J Fennie
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA
| | - Lena F Kourkoutis
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA
- Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, New York 14853, USA
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49
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Kim H, Shim JH, Kim S, Park JH, Kim K, Min BI. Unusual Pressure-Induced Quantum Phase Transition from Superconducting to Charge-Density Wave State in Rare-Earth-Based Heusler LuPd_{2}In Compound. PHYSICAL REVIEW LETTERS 2020; 125:157001. [PMID: 33095605 DOI: 10.1103/physrevlett.125.157001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 03/10/2020] [Accepted: 09/10/2020] [Indexed: 06/11/2023]
Abstract
We investigate the pressure effects on the electronic structures and phonon properties of rare-earth-based cubic-Heusler compound LuPd_{2}In, on the basis of ab initio density functional theory. We find the occurrence of intriguing phase transition from the superconducting (SC) to charge-density wave (CDW) state under pressure (P), which is quite unusual in that the pressure is detrimental to the CDW state in usual systems. The SC transition temperature T_{C} of LuPd_{2}In increases first with increasing pressure, up to P_{C}≈28 GPa, above which a quantum phase transition into the CDW state takes place. This extraordinary transition originates from the occurrence of phonon softening instability at a special q=M in the Brillouin zone. We thus propose that LuPd_{2}In is a quite unique material, in which the CDW quantum critical point is realized under the SC dome by applying the pressure.
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Affiliation(s)
- Heejung Kim
- Department of Physics, POSTECH, Pohang 37673, Korea
- MPPHC-CPM, Max Planck POSTECH/Korea Research Initiative, Pohang 37673, Korea
| | - J H Shim
- Department of Physics, POSTECH, Pohang 37673, Korea
- Department of Chemistry, POSTECH, Pohang 37673, Korea
| | - Sooran Kim
- Department of Physics Education, Kyungpook National University, Daegu 41566, Korea
| | - Jae-Hoon Park
- Department of Physics, POSTECH, Pohang 37673, Korea
- MPPHC-CPM, Max Planck POSTECH/Korea Research Initiative, Pohang 37673, Korea
- Division of Advanced Materials Science, POSTECH, Pohang 37673, Korea
| | - Kyoo Kim
- Department of Physics, POSTECH, Pohang 37673, Korea
- MPPHC-CPM, Max Planck POSTECH/Korea Research Initiative, Pohang 37673, Korea
- Korea Atomic Energy Research Institute (KAERI), 111 Daedeok-daero, Daejeon 34057, Korea
| | - B I Min
- Department of Physics, POSTECH, Pohang 37673, Korea
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50
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Bianco R, Monacelli L, Calandra M, Mauri F, Errea I. Weak Dimensionality Dependence and Dominant Role of Ionic Fluctuations in the Charge-Density-Wave Transition of NbSe_{2}. PHYSICAL REVIEW LETTERS 2020; 125:106101. [PMID: 32955304 DOI: 10.1103/physrevlett.125.106101] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/30/2020] [Indexed: 06/11/2023]
Abstract
Contradictory experiments have been reported about the dimensionality effect on the charge-density-wave transition in 2H NbSe_{2}. While scanning tunneling experiments on single layers grown by molecular beam epitaxy measure a charge-density-wave transition temperature in the monolayer similar to the bulk, around 33 K, Raman experiments on exfoliated samples observe a large enhancement of the transition temperature up to 145 K. By employing a nonperturbative approach to deal with anharmonicity, we calculate from first principles the temperature dependence of the phonon spectra both for bulk and monolayer. In both cases, the charge-density-wave transition temperature is estimated as the temperature at which the phonon energy of the mode driving the structural instability vanishes. The obtained transition temperature in the bulk is around 59 K, in rather good agreement with experiments, and it is just slightly increased in the single-layer limit to 73 K, showing the weak dependence of the transition on dimensionality. Environmental factors could motivate the disagreement between the transition temperatures reported by experiments. Our analysis also demonstrates the predominance of ionic fluctuations over electronic ones in the melting of the charge-density-wave order.
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Affiliation(s)
- Raffaello Bianco
- Centro de Física de Materiales (CSIC-UPV/EHU), Manuel de Lardizabal pasealekua 5, 20018 Donostia/San Sebastián, Spain
| | - Lorenzo Monacelli
- Dipartimento di Fisica, Università di Roma Sapienza, Piazzale Aldo Moro 5, I-00185 Roma, Italy
- Graphene Labs, Fondazione Istituto Italiano di Tecnologia, Via Morego, I-16163 Genova, Italy
| | - Matteo Calandra
- Graphene Labs, Fondazione Istituto Italiano di Tecnologia, Via Morego, I-16163 Genova, Italy
- Dipartimento di Fisica, Università di Trento, Via Sommarive 14, 38123 Povo, Italy
- Sorbonne Université, CNRS, Institut des Nanosciences de Paris, UMR7588, F-75252 Paris, France
| | - Francesco Mauri
- Dipartimento di Fisica, Università di Roma Sapienza, Piazzale Aldo Moro 5, I-00185 Roma, Italy
- Graphene Labs, Fondazione Istituto Italiano di Tecnologia, Via Morego, I-16163 Genova, Italy
| | - Ion Errea
- Centro de Física de Materiales (CSIC-UPV/EHU), Manuel de Lardizabal pasealekua 5, 20018 Donostia/San Sebastián, Spain
- Fisika Aplikatua 1 Saila, Gipuzkoako Ingeniaritza Eskola, University of the Basque Country (UPV/EHU), Europa Plaza 1, 20018 Donostia/San Sebastián, Spain
- Donostia International Physics Center (DIPC), Manuel Lardizabal pasealekua 4, 20018 Donostia/San Sebastián, Spain
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