1
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Domröse T, Fernandez N, Eckel C, Rossnagel K, Weitz RT, Ropers C. Nanoscale Operando Imaging of Electrically Driven Charge-Density Wave Phase Transitions. NANO LETTERS 2024; 24:12476-12485. [PMID: 39316412 DOI: 10.1021/acs.nanolett.4c03324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/25/2024]
Abstract
Structural transformations in strongly correlated materials promise efficient and fast control of materials' properties via electrical or optical stimulation. The desired functionality of devices operating based on phase transitions, however, will also be influenced by nanoscale heterogeneity. Experimentally characterizing the relationship between microstructure and phase switching remains challenging, as nanometer resolution and high sensitivity to subtle structural modifications are required. Here, we demonstrate nanoimaging of a current-induced phase transformation in the charge-density wave (CDW) material 1T-TaS2. Combining electrical characterizations with tailored contrast enhancement, we correlate macroscopic resistance changes with the nanoscale nucleation and growth of CDW phase domains. In particular, we locally determine the transformation barrier in the presence of dislocations and strain, underlining their non-negligible impact on future functional devices. Thereby, our results demonstrate the merit of tailored contrast enhancement and beam shaping for advanced operando microscopy of quantum materials and devices.
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Affiliation(s)
- Till Domröse
- Department of Ultrafast Dynamics, Max Planck Institute for Multidisciplinary Sciences, 37077 Göttingen, Germany
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, 37077 Göttingen, Germany
| | - Noelia Fernandez
- 1st Institute of Physics, University of Göttingen, 37077 Göttingen, Germany
| | - Christian Eckel
- 1st Institute of Physics, University of Göttingen, 37077 Göttingen, Germany
| | - Kai Rossnagel
- Institute of Experimental and Applied Physics, Kiel University, 24098 Kiel, Germany
- Ruprecht Haensel Laboratory, Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany
| | - R Thomas Weitz
- 1st Institute of Physics, University of Göttingen, 37077 Göttingen, Germany
- International Center for Advanced Studies of Energy Conversion (ICASEC), University of Göttingen, 37077 Göttingen, Germany
| | - Claus Ropers
- Department of Ultrafast Dynamics, Max Planck Institute for Multidisciplinary Sciences, 37077 Göttingen, Germany
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, 37077 Göttingen, Germany
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2
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Hart JL, Pan H, Siddique S, Schnitzer N, Mallayya K, Xu S, Kourkoutis LF, Kim EA, Cha JJ. Real-space visualization of a defect-mediated charge density wave transition. Proc Natl Acad Sci U S A 2024; 121:e2402129121. [PMID: 39106309 PMCID: PMC11331100 DOI: 10.1073/pnas.2402129121] [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: 01/30/2024] [Accepted: 06/14/2024] [Indexed: 08/09/2024] Open
Abstract
We study the coupled charge density wave (CDW) and insulator-to-metal transitions in the 2D quantum material 1T-TaS2. By applying in situ cryogenic 4D scanning transmission electron microscopy with in situ electrical resistance measurements, we directly visualize the CDW transition and establish that the transition is mediated by basal dislocations (stacking solitons). We find that dislocations can both nucleate and pin the transition and locally alter the transition temperature Tc by nearly ~75 K. This finding was enabled by the application of unsupervised machine learning to cluster five-dimensional, terabyte scale datasets, which demonstrate a one-to-one correlation between resistance-a global property-and local CDW domain-dislocation dynamics, thereby linking the material microstructure to device properties. This work represents a major step toward defect-engineering of quantum materials, which will become increasingly important as we aim to utilize such materials in real devices.
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Affiliation(s)
- James L. Hart
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY14853
| | - Haining Pan
- Department of Physics, Cornell University, Ithaca, NY14853
| | - Saif Siddique
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY14853
| | - Noah Schnitzer
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY14853
| | | | - Shiyu Xu
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY14853
| | - Lena F. Kourkoutis
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY14853
- Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY14853
| | - Eun-ah Kim
- Department of Physics, Cornell University, Ithaca, NY14853
- Department of Physics, Ewha Womans University, Seoul03760, South Korea
| | - Judy J. Cha
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY14853
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3
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Griffiths J, Suzana AF, Wu L, Marks SD, Esposito V, Boutet S, Evans PG, Mitchell JF, Dean MPM, Keen DA, Robinson I, Billinge SJL, Bozin ES. Resolving length-scale-dependent transient disorder through an ultrafast phase transition. NATURE MATERIALS 2024; 23:1041-1047. [PMID: 38871940 PMCID: PMC11294184 DOI: 10.1038/s41563-024-01927-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Accepted: 05/19/2024] [Indexed: 06/15/2024]
Abstract
Material functionality can be strongly determined by structure extending only over nanoscale distances. The pair distribution function presents an opportunity for structural studies beyond idealized crystal models and to investigate structure over varying length scales. Applying this method with ultrafast time resolution has the potential to similarly disrupt the study of structural dynamics and phase transitions. Here we demonstrate such a measurement of CuIr2S4 optically pumped from its low-temperature Ir-dimerized phase. Dimers are optically suppressed without spatial correlation, generating a structure whose level of disorder strongly depends on the length scale. The redevelopment of structural ordering over tens of picoseconds is directly tracked over both space and time as a transient state is approached. This measurement demonstrates the crucial role of local structure and disorder in non-equilibrium processes as well as the feasibility of accessing this information with state-of-the-art XFEL facilities.
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Affiliation(s)
- Jack Griffiths
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, NY, USA.
| | - Ana F Suzana
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, NY, USA
| | - Longlong Wu
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, NY, USA
| | - Samuel D Marks
- Department of Materials Science and Engineering, University of Wisconsin, Madison, WI, USA
| | | | | | - Paul G Evans
- Department of Materials Science and Engineering, University of Wisconsin, Madison, WI, USA
| | - J F Mitchell
- Materials Science Division, Argonne National Laboratory, Lemont, IL, USA
| | - Mark P M Dean
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, NY, USA
| | - David A Keen
- ISIS Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Didcot, UK
| | - Ian Robinson
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, NY, USA
- London Centre for Nanotechnology, University College London, London, UK
| | - Simon J L Billinge
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, NY, USA
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, USA
| | - Emil S Bozin
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, NY, USA.
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4
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Vodeb J, Diego M, Vaskivskyi Y, Logaric L, Gerasimenko Y, Kabanov V, Lipovsek B, Topic M, Mihailovic D. Non-equilibrium quantum domain reconfiguration dynamics in a two-dimensional electronic crystal and a quantum annealer. Nat Commun 2024; 15:4836. [PMID: 38844460 PMCID: PMC11156939 DOI: 10.1038/s41467-024-49179-z] [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: 06/13/2023] [Accepted: 05/23/2024] [Indexed: 06/09/2024] Open
Abstract
Relaxation dynamics of complex many-body quantum systems trapped into metastable states is a very active field of research from both the theoretical and experimental point of view with implications in a wide array of topics from macroscopic quantum tunnelling and nucleosynthesis to non-equilibrium superconductivity and energy-efficient memory devices. In this work, we investigate quantum domain reconfiguration dynamics in the electronic superlattice of a quantum material using time-resolved scanning tunneling microscopy and unveil a crossover from temperature to noisy quantum fluctuation dominated dynamics. The process is modeled using a programmable superconducting quantum annealer in which qubit interconnections correspond directly to the microscopic interactions between electrons in the quantum material. Crucially, the dynamics of both the experiment and quantum simulation is driven by spectrally similar pink noise. We find that the simulations reproduce the emergent time evolution and temperature dependence of the experimentally observed electronic domain dynamics.
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Affiliation(s)
- Jaka Vodeb
- Jozef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia.
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000, Ljubljana, Slovenia.
- Institute for Advanced Simulation, Jülich Supercomputing Centre, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425, Jülich, Germany.
| | - Michele Diego
- Jozef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia
| | - Yevhenii Vaskivskyi
- Jozef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000, Ljubljana, Slovenia
| | - Leonard Logaric
- Jozef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia
| | | | - Viktor Kabanov
- Jozef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia
| | - Benjamin Lipovsek
- Faculty for Electrical Engineering, University of Ljubljana, Tržaška 25, 1000, Ljubljana, Slovenia
| | - Marko Topic
- Faculty for Electrical Engineering, University of Ljubljana, Tržaška 25, 1000, Ljubljana, Slovenia
| | - Dragan Mihailovic
- Jozef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia.
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000, Ljubljana, Slovenia.
- CENN Nanocenter, Jamova 39, 1000, Ljubljana, Slovenia.
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5
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Cheng WN, Niu M, Meng Y, Han X, Qiao J, Zhang J, Zhao X. Engineering Charge Density Waves by Stackingtronics in Tantalum Disulfide. NANO LETTERS 2024; 24:6441-6449. [PMID: 38757836 DOI: 10.1021/acs.nanolett.4c01771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
In the realm of condensed matter physics and materials science, charge density waves (CDWs) have emerged as a captivating way to modulate correlated electronic phases and electron oscillations in quantum materials. However, collectively and efficiently tuning CDW order is a formidable challenge. Herein, we introduced a novel way to modulate the CDW order in 1T-TaS2 via stacking engineering. By introducing shear strain during the electrochemical exfoliation, the thermodynamically stable AA-stacked TaS2 consecutively transform into metastable ABC stacking, resulting in unique 3a × 1a CDW order. By decoupling atom coordinates, we atomically deciphered the 3D subtle structural variations in trilayer samples. As suggested by density functional theory (DFT) calculations, the origin of CDWs is presumably due to collective excitations and charge modulation. Therefore, our works shed light on a new avenue to collectively modulate the CDW order via stackingtronics and unveiled novel mechanisms for triggering CDW formation via charge modulation.
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Affiliation(s)
- Wing Ni Cheng
- School of Materials Science and Engineering, Peking University, Beijing 100871, China
| | - Mengmeng Niu
- MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices & Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology, Beijing 100081, China
| | - Yuan Meng
- School of Materials Science and Engineering, Peking University, Beijing 100871, China
| | - Xiaocang Han
- School of Materials Science and Engineering, Peking University, Beijing 100871, China
| | - Jingsi Qiao
- MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices & Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology, Beijing 100081, China
| | - Jin Zhang
- School of Materials Science and Engineering, Peking University, Beijing 100871, China
| | - Xiaoxu Zhao
- School of Materials Science and Engineering, Peking University, Beijing 100871, China
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6
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Nhat Quyen N, Tzeng WY, Hsu CE, Lin IA, Chen WH, Jia HH, Wang SC, Liu CE, Chen YS, Chen WL, Chou TL, Wang IT, Kuo CN, Lin CL, Wu CT, Lin PH, Weng SC, Cheng CM, Kuo CY, Tu CM, Chu MW, Chang YM, Lue CS, Hsueh HC, Luo CW. Three-dimensional ultrafast charge-density-wave dynamics in CuTe. Nat Commun 2024; 15:2386. [PMID: 38493205 PMCID: PMC10944522 DOI: 10.1038/s41467-024-46615-y] [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: 03/28/2023] [Accepted: 03/04/2024] [Indexed: 03/18/2024] Open
Abstract
Charge density waves (CDWs) involved with electronic and phononic subsystems simultaneously are a common quantum state in solid-state physics, especially in low-dimensional materials. However, CDW phase dynamics in various dimensions are yet to be studied, and their phase transition mechanism is currently moot. Here we show that using the distinct temperature evolution of orientation-dependent ultrafast electron and phonon dynamics, different dimensional CDW phases are verified in CuTe. When the temperature decreases, the shrinking of c-axis length accompanied with the appearance of interchain and interlayer interactions causes the quantum fluctuations (QF) of the CDW phase until 220 K. At T < 220 K, the CDWs on the different ab-planes are finally locked with each other in anti-phase to form a CDW phase along the c-axis. This study shows the dimension evolution of CDW phases in one CDW system and their stabilized mechanisms in different temperature regimes.
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Grants
- 112-2119-M-A49-012-MBK Ministry of Science and Technology, Taiwan (Ministry of Science and Technology of Taiwan)
- 109-2112-M-009-020-MY3 Ministry of Science and Technology, Taiwan (Ministry of Science and Technology of Taiwan)
- 109-2124-M-009-003-MY3 Ministry of Science and Technology, Taiwan (Ministry of Science and Technology of Taiwan)
- 109-2119-M-002 -026 -MY3 Ministry of Science and Technology, Taiwan (Ministry of Science and Technology of Taiwan)
- 108-2112-M-002-013-MY3 Ministry of Science and Technology, Taiwan (Ministry of Science and Technology of Taiwan)
- 111-2124-M-213-001 Ministry of Science and Technology, Taiwan (Ministry of Science and Technology of Taiwan)
- 108-2112-M-002 -013 -MY3 Ministry of Science and Technology, Taiwan (Ministry of Science and Technology of Taiwan)
- 109-2119-M-002 -026 -MY3 Ministry of Science and Technology, Taiwan (Ministry of Science and Technology of Taiwan)
- 112-2124-M-006-009 Ministry of Science and Technology, Taiwan (Ministry of Science and Technology of Taiwan)
- 110-2112-M-032-014-MY3 Ministry of Science and Technology, Taiwan (Ministry of Science and Technology of Taiwan)
- Ministry of Education (Ministry of Education, Republic of China (Taiwan))
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Affiliation(s)
- Nguyen Nhat Quyen
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
| | - Wen-Yen Tzeng
- Department of Electronic Engineering, National Formosa University, Yunlin, 632, Taiwan
| | - Chih-En Hsu
- Department of Physics, Tamkang University, New Taipei City, 251301, Taiwan
| | - I-An Lin
- Department of Physics, Tamkang University, New Taipei City, 251301, Taiwan
| | - Wan-Hsin Chen
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
| | - Hao-Hsiang Jia
- National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan
| | - Sheng-Chiao Wang
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
| | - Cheng-En Liu
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
| | - Yu-Sheng Chen
- National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan
| | - Wei-Liang Chen
- Center for Condensed Matter Sciences, National Taiwan University, Taipei, 10617, Taiwan
| | - Ta-Lei Chou
- Center for Condensed Matter Sciences, National Taiwan University, Taipei, 10617, Taiwan
| | - I-Ta Wang
- Center for Condensed Matter Sciences, National Taiwan University, Taipei, 10617, Taiwan
| | - Chia-Nung Kuo
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Chun-Liang Lin
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
| | - Chien-Te Wu
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
- Physics Division, National Center for Theoretical Sciences, Taipei, Taiwan
| | - Ping-Hui Lin
- National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan
| | - Shih-Chang Weng
- National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan
| | - Cheng-Maw Cheng
- National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan
| | - Chang-Yang Kuo
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
- National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan
| | - Chien-Ming Tu
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
- Undergraduate Degree Program of Systems Engineering and Technology, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
- Chung Cheng Institute of Technology, National Defense University, Taoyuan, 335009, Taiwan
| | - Ming-Wen Chu
- Center for Condensed Matter Sciences, National Taiwan University, Taipei, 10617, Taiwan
- Center of Atomic Initiative for New Materials (AI-MAT), National Taiwan University, Taipei, 10617, Taiwan
| | - Yu-Ming Chang
- Center for Condensed Matter Sciences, National Taiwan University, Taipei, 10617, Taiwan
- Center of Atomic Initiative for New Materials (AI-MAT), National Taiwan University, Taipei, 10617, Taiwan
| | - Chin Shan Lue
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan.
- Taiwan Consortium of Emergent Crystalline Materials (TCECM), National Science and Technology Council, Taipei, 10601, Taiwan.
| | - Hung-Chung Hsueh
- Department of Physics, Tamkang University, New Taipei City, 251301, Taiwan.
| | - Chih-Wei Luo
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan.
- National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan.
- Taiwan Consortium of Emergent Crystalline Materials (TCECM), National Science and Technology Council, Taipei, 10601, Taiwan.
- Institute of Physics and Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan.
- Department of Physics, University of Washington, Seattle, Washington, 98195, USA.
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7
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Sung SH, Agarwal N, El Baggari I, Kezer P, Goh YM, Schnitzer N, Shen JM, Chiang T, Liu Y, Lu W, Sun Y, Kourkoutis LF, Heron JT, Sun K, Hovden R. Endotaxial stabilization of 2D charge density waves with long-range order. Nat Commun 2024; 15:1403. [PMID: 38360698 PMCID: PMC10869719 DOI: 10.1038/s41467-024-45711-3] [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: 07/31/2023] [Accepted: 01/30/2024] [Indexed: 02/17/2024] Open
Abstract
Charge density waves are emergent quantum states that spontaneously reduce crystal symmetry, drive metal-insulator transitions, and precede superconductivity. In low-dimensions, distinct quantum states arise, however, thermal fluctuations and external disorder destroy long-range order. Here we stabilize ordered two-dimensional (2D) charge density waves through endotaxial synthesis of confined monolayers of 1T-TaS2. Specifically, an ordered incommensurate charge density wave (oIC-CDW) is realized in 2D with dramatically enhanced amplitude and resistivity. By enhancing CDW order, the hexatic nature of charge density waves becomes observable. Upon heating via in-situ TEM, the CDW continuously melts in a reversible hexatic process wherein topological defects form in the charge density wave. From these results, new regimes of the CDW phase diagram for 1T-TaS2 are derived and consistent with the predicted emergence of vestigial quantum order.
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Affiliation(s)
- Suk Hyun Sung
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Nishkarsh Agarwal
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | | | - Patrick Kezer
- Department of Electrical and Computer Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Yin Min Goh
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA
| | - Noah Schnitzer
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, 14853, USA
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, NY, 14853, USA
| | - Jeremy M Shen
- Department of Electrical and Computer Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Tony Chiang
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Yu Liu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, 230031, PR China
| | - Wenjian Lu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, 230031, PR China
| | - Yuping Sun
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, 230031, PR China
- Collaborative Innovation Centre of Advanced Microstructures, Nanjing University, Nanjing, 210093, PR China
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, 230031, PR China
| | - Lena F Kourkoutis
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, NY, 14853, USA
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, 14853, USA
| | - John T Heron
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
- Applied Physics Program, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Kai Sun
- Department of Physics, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Robert Hovden
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, 48109, USA.
- Applied Physics Program, University of Michigan, Ann Arbor, MI, 48109, USA.
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8
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Song X, Huang X, Yang H, Jia L, Zhang Q, Huang Y, Wu X, Liu L, Gao HJ, Wang Y. Robust Behavior of Charge Density Wave Quantum Motif Star-of-David in 2D NbSe 2 Nanocrystals. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2305159. [PMID: 37635109 DOI: 10.1002/smll.202305159] [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: 06/20/2023] [Revised: 08/02/2023] [Indexed: 08/29/2023]
Abstract
Charge density wave (CDW) is a typical collective phenomenon, and the phase change is generally accompanied by electronic transition with potential device applications. For the continuous miniaturization of devices, it is important to investigate the size effect down to the nanoscale. In this work, single-layer (SL) 1T-NbSe2 islands provide an ideal research platform to investigate the size effect on CDW arrangement and electronic states. The CDW motifs (Star-of-David [SOD]) at the island border are along the edge, and those at the interior tend to arrange in a triangular lattice for islands as small as 5 nm. Interestingly, in some small islands, the SOD clusters rearrange into a square-like lattice, and each SOD cluster remains robust as a quantum motif, both in the sense of geometry and electronic structures. Moreover, the electronic structure at the center of the small islands is downwards shifted compared to the big islands, explained by the spatial extension of the band bending originating from the edge of the islands. These findings reveal the robust behavior of CDW motifs down to the nanoscale and provide new insights into the size-limiting effect on 2D2D CDW ordering and electronic states down to a few nanometer extremes.
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Affiliation(s)
- Xuan Song
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, 100081, China
| | - Xinyu Huang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, 100081, China
| | - Han Yang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, 100081, China
| | - Liangguang Jia
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, 100081, China
| | - Quanzhen Zhang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, 100081, China
| | - Yuan Huang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, 100081, China
| | - Xu Wu
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, 100081, China
| | - Liwei Liu
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, 100081, China
| | - Hong-Jun Gao
- Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yeliang Wang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, 100081, China
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9
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Husremović S, Goodge BH, Erodici MP, Inzani K, Mier A, Ribet SM, Bustillo KC, Taniguchi T, Watanabe K, Ophus C, Griffin SM, Bediako DK. Encoding multistate charge order and chirality in endotaxial heterostructures. Nat Commun 2023; 14:6031. [PMID: 37758701 PMCID: PMC10533556 DOI: 10.1038/s41467-023-41780-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 09/16/2023] [Indexed: 09/29/2023] Open
Abstract
High-density phase change memory (PCM) storage is proposed for materials with multiple intermediate resistance states, which have been observed in 1T-TaS2 due to charge density wave (CDW) phase transitions. However, the metastability responsible for this behavior makes the presence of multistate switching unpredictable in TaS2 devices. Here, we demonstrate the fabrication of nanothick verti-lateral H-TaS2/1T-TaS2 heterostructures in which the number of endotaxial metallic H-TaS2 monolayers dictates the number of resistance transitions in 1T-TaS2 lamellae near room temperature. Further, we also observe optically active heterochirality in the CDW superlattice structure, which is modulated in concert with the resistivity steps, and we show how strain engineering can be used to nucleate these polytype conversions. This work positions the principle of endotaxial heterostructures as a promising conceptual framework for reliable, non-volatile, and multi-level switching of structure, chirality, and resistance.
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Affiliation(s)
- Samra Husremović
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA
| | - Berit H Goodge
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA
- Max-Planck-Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187, Dresden, Germany
| | - Matthew P Erodici
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA
| | - Katherine Inzani
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Alberto Mier
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA
| | - Stephanie M Ribet
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA
- International Institute of Nanotechnology, Northwestern University, Evanston, IL, 60208, USA
| | - Karen C Bustillo
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Takashi Taniguchi
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, 305-0044, Japan
| | - Kenji Watanabe
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, 305-0044, Japan
| | - Colin Ophus
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Sinéad M Griffin
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - D Kwabena Bediako
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA.
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
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10
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Liu G, Qiu T, He K, Liu Y, Lin D, Ma Z, Huang Z, Tang W, Xu J, Watanabe K, Taniguchi T, Gao L, Wen J, Liu JM, Yan B, Xi X. Electrical switching of ferro-rotational order in nanometre-thick 1T-TaS 2 crystals. NATURE NANOTECHNOLOGY 2023; 18:854-860. [PMID: 37169899 DOI: 10.1038/s41565-023-01403-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 04/14/2023] [Indexed: 05/13/2023]
Abstract
Hysteretic switching of domain states is a salient characteristic of all ferroic materials and the foundation for their multifunctional applications. Ferro-rotational order is emerging as a type of ferroic order that features structural rotations, but control over state switching remains elusive due to its invariance under both time reversal and spatial inversion. Here we demonstrate electrical switching of ferro-rotational domain states in the charge-density-wave phases of nanometre-thick 1T-TaS2 crystals. Cooling from the high-symmetry phase to the ferro-rotational phase under an external electric field induces domain state switching and domain wall formation, which is realized in a simple two-terminal configuration using a volt-scale bias. Although the electric field does not couple with the order due to symmetry mismatch, it drives domain wall propagation to give rise to reversible, durable and non-volatile isothermal state switching at room temperature. These results offer a route to the manipulation of ferro-rotational order and its nanoelectronic applications.
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Affiliation(s)
- Gan Liu
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China
| | - Tianyu Qiu
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China
| | - Kuanyu He
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China
| | - Yizhou Liu
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Dongjing Lin
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China
| | - Zhen Ma
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China
- Institute for Advanced Materials, Hubei Normal University, Huangshi, China
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai, China
| | - Zhentao Huang
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China
| | - Wenna Tang
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China
| | - Jie Xu
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - Libo Gao
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
| | - Jinsheng Wen
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
| | - Jun-Ming Liu
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
| | - Binghai Yan
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel.
| | - Xiaoxiang Xi
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China.
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China.
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11
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Hart JL, Siddique S, Schnitzer N, Kourkoutis LF, Cha JJ. Pulse-Induced CDW Transitions in 1T-TaS2 Studied with in situ Cryo-TEM and Electric Biasing. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:1714-1715. [PMID: 37613906 DOI: 10.1093/micmic/ozad067.886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- James L Hart
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, USA
| | - Saif Siddique
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, USA
| | - Noah Schnitzer
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, USA
| | - Lena F Kourkoutis
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, USA
- Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY, USA
| | - Judy J Cha
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, USA
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12
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Pan X, Yang T, Bai H, Peng J, Li L, Jing F, Qiu H, Liu H, Hu Z. Controllable Synthesis and Charge Density Wave Phase Transitions of Two-Dimensional 1T-TaS 2 Crystals. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:nano13111806. [PMID: 37299709 DOI: 10.3390/nano13111806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 06/02/2023] [Accepted: 06/02/2023] [Indexed: 06/12/2023]
Abstract
1T-TaS2 has attracted much attention recently due to its abundant charge density wave phases. In this work, high-quality two-dimensional 1T-TaS2 crystals were successfully synthesized by a chemical vapor deposition method with controllable layer numbers, confirmed by the structural characterization. Based on the as-grown samples, their thickness-dependency nearly commensurate charge density wave/commensurate charge density wave phase transitions was revealed by the combination of the temperature-dependent resistance measurements and Raman spectra. The phase transition temperature increased with increasing thickness, but no apparent phase transition was found on the 2~3 nm thick crystals from temperature-dependent Raman spectra. The transition hysteresis loops due to temperature-dependent resistance changes of 1T-TaS2 can be used for memory devices and oscillators, making 1T-TaS2 a promising material for various electronic applications.
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Affiliation(s)
- Xiaoguang Pan
- Tianjin Key Laboratory of Functional Crystal Materials, Institute of Functional Crystals, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China
| | - Tianwen Yang
- Tianjin Key Laboratory of Functional Crystal Materials, Institute of Functional Crystals, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China
| | - Hangxin Bai
- Tianjin Key Laboratory of Functional Crystal Materials, Institute of Functional Crystals, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China
| | - Jiangbo Peng
- Tianjin Key Laboratory of Functional Crystal Materials, Institute of Functional Crystals, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China
| | - Lujie Li
- Tianjin Key Laboratory of Functional Crystal Materials, Institute of Functional Crystals, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China
| | - Fangli Jing
- Tianjin Key Laboratory of Functional Crystal Materials, Institute of Functional Crystals, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China
| | - Hailong Qiu
- Tianjin Key Laboratory of Functional Crystal Materials, Institute of Functional Crystals, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China
| | - Hongjun Liu
- Tianjin Key Laboratory of Functional Crystal Materials, Institute of Functional Crystals, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China
| | - Zhanggui Hu
- Tianjin Key Laboratory of Functional Crystal Materials, Institute of Functional Crystals, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China
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13
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Barani Z, Geremew T, Stokey M, Sesing N, Taheri M, Hilfiker MJ, Kargar F, Schubert M, Salguero TT, Balandin AA. Quantum Composites with Charge-Density-Wave Fillers. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2209708. [PMID: 36812299 DOI: 10.1002/adma.202209708] [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: 10/20/2022] [Revised: 02/12/2023] [Indexed: 05/12/2023]
Abstract
A unique class of advanced materials-quantum composites based on polymers with fillers composed of a van der Waals quantum material that reveals multiple charge-density-wave quantum condensate phases-is demonstrated. Materials that exhibit quantum phenomena are typically crystalline, pure, and have few defects because disorder destroys the coherence of the electrons and phonons, leading to collapse of the quantum states. The macroscopic charge-density-wave phases of filler particles after multiple composite processing steps are successfully preserved in this work. The prepared composites display strong charge-density-wave phenomena even above room temperature. The dielectric constant experiences more than two orders of magnitude enhancement while the material maintains its electrically insulating properties, opening a venue for advanced applications in energy storage and electronics. The results present a conceptually different approach for engineering the properties of materials, extending the application domain for van der Waals materials.
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Affiliation(s)
- Zahra Barani
- Phonon Optimized Engineered Materials Center, Department of Electrical and Computer Engineering, University of California, Riverside, Riverside, CA, 92521, USA
| | - Tekwam Geremew
- Phonon Optimized Engineered Materials Center, Department of Electrical and Computer Engineering, University of California, Riverside, Riverside, CA, 92521, USA
| | - Megan Stokey
- Department of Electrical and Computer Engineering, University of Nebraska, Lincoln, NE, 68588, USA
| | - Nicholas Sesing
- Department of Chemistry, University of Georgia, Athens, GA, 30602, USA
| | - Maedeh Taheri
- Phonon Optimized Engineered Materials Center, Department of Electrical and Computer Engineering, University of California, Riverside, Riverside, CA, 92521, USA
| | - Matthew J Hilfiker
- Department of Electrical and Computer Engineering, University of Nebraska, Lincoln, NE, 68588, USA
| | - Fariborz Kargar
- Phonon Optimized Engineered Materials Center, Department of Electrical and Computer Engineering, University of California, Riverside, Riverside, CA, 92521, USA
| | - Mathias Schubert
- Department of Electrical and Computer Engineering, University of Nebraska, Lincoln, NE, 68588, USA
| | - Tina T Salguero
- Department of Chemistry, University of Georgia, Athens, GA, 30602, USA
| | - Alexander A Balandin
- Phonon Optimized Engineered Materials Center, Department of Electrical and Computer Engineering, University of California, Riverside, Riverside, CA, 92521, USA
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14
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Zhao Y, Nie Z, Hong H, Qiu X, Han S, Yu Y, Liu M, Qiu X, Liu K, Meng S, Tong L, Zhang J. Spectroscopic visualization and phase manipulation of chiral charge density waves in 1T-TaS 2. Nat Commun 2023; 14:2223. [PMID: 37076513 PMCID: PMC10115830 DOI: 10.1038/s41467-023-37927-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 03/30/2023] [Indexed: 04/21/2023] Open
Abstract
The chiral charge density wave is a many-body collective phenomenon in condensed matter that may play a role in unconventional superconductivity and topological physics. Two-dimensional chiral charge density waves provide the building blocks for the fabrication of various stacking structures and chiral homostructures, in which physical properties such as chiral currents and the anomalous Hall effect may emerge. Here, we demonstrate the phase manipulation of two-dimensional chiral charge density waves and the design of in-plane chiral homostructures in 1T-TaS2. We use chiral Raman spectroscopy to directly monitor the chirality switching of the charge density wave-revealing a temperature-mediated reversible chirality switching. We find that interlayer stacking favours homochirality configurations, which is confirmed by first-principles calculations. By exploiting the interlayer chirality-locking effect, we realise in-plane chiral homostructures in 1T-TaS2. Our results provide a versatile way to manipulate chiral collective phases by interlayer coupling in layered van der Waals semiconductors.
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Affiliation(s)
- Yan Zhao
- College of Chemistry and Molecular Engineering, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing, 100871, P. R. China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, P. R. China
| | - Zhengwei Nie
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Hao Hong
- State Key Lab for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing, 100871, P. R. China
| | - Xia Qiu
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
| | - Shiyi Han
- College of Chemistry and Molecular Engineering, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing, 100871, P. R. China
| | - Yue Yu
- College of Chemistry and Molecular Engineering, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing, 100871, P. R. China
| | - Mengxi Liu
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
| | - Xiaohui Qiu
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
| | - Kaihui Liu
- State Key Lab for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing, 100871, P. R. China
| | - Sheng Meng
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, P. R. China.
| | - Lianming Tong
- College of Chemistry and Molecular Engineering, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing, 100871, P. R. China.
| | - Jin Zhang
- College of Chemistry and Molecular Engineering, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing, 100871, P. R. China
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15
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Liu L, Song X, Dai J, Yang H, Chen Y, Huang X, Huang Z, Ji H, Zhang Y, Wu X, Sun JT, Zhang Q, Zhou J, Huang Y, Qiao J, Ji W, Gao HJ, Wang Y. Unveiling Electronic Behaviors in Heterochiral Charge-Density-Wave Twisted Stacking Materials with 1.25 nm Unit Dependence. ACS NANO 2023; 17:2702-2710. [PMID: 36661840 DOI: 10.1021/acsnano.2c10841] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Layered charge-density-wave (CDW) materials have gained increasing interest due to their CDW stacking-dependent electronic properties for practical applications. Among the large family of CDW materials, those with star of David (SOD) patterns are very important due to the potentials for quantum spin liquid and related device applications. However, the spatial extension and the spin coupling information down to the nanoscale remain elusive. Here, we report the study of heterochiral CDW stackings in bilayer (BL) NbSe2 with high spatial resolution. We reveal that there exist well-defined heterochiral stackings, which have inhomogeneous electronic states among neighboring CDW units (star of David, SOD), significantly different from the homogeneous electronic states in the homochiral stackings. Intriguingly, the different electronic behaviors are spatially localized within each SOD with a unit size of 1.25 nm, and the gap sizes are determined by the different types of SOD stackings. Density functional theory (DFT) calculations match the experimental measurements well and reveal the SOD-stacking-dependent correlated electronic states and antiferromagnetic/ferromagnetic couplings. Our findings give a deep understanding of the spatial distribution of interlayer stacking and the delicate modulation of the spintronic states, which is very helpful for CDW-based nanoelectronic devices.
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Affiliation(s)
- Liwei Liu
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Xuan Song
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Jiaqi Dai
- Beijing Key Laboratory of Optoelectronic Functional Materials and Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing 100872, People's Republic of China
| | - Han Yang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Yaoyao Chen
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Xinyu Huang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Zeping Huang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Hongyan Ji
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Yu Zhang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Xu Wu
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Jia-Tao Sun
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Quanzhen Zhang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Jiadong Zhou
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Yuan Huang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Jingsi Qiao
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Wei Ji
- Beijing Key Laboratory of Optoelectronic Functional Materials and Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing 100872, People's Republic of China
| | - Hong-Jun Gao
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Yeliang Wang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, People's Republic of China
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16
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Taheri M, Brown J, Rehman A, Sesing N, Kargar F, Salguero TT, Rumyantsev S, Balandin AA. Electrical Gating of the Charge-Density-Wave Phases in Two-Dimensional h-BN/1T-TaS 2 Devices. ACS NANO 2022; 16:18968-18977. [PMID: 36315105 DOI: 10.1021/acsnano.2c07876] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
We report on the electrical gating of the charge-density-wave phases and current in h-BN-capped three-terminal 1T-TaS2 heterostructure devices. It is demonstrated that the application of a gate bias can shift the source-drain current-voltage hysteresis associated with the transition between the nearly commensurate and incommensurate charge-density-wave phases. The evolution of the hysteresis and the presence of abrupt spikes in the current while sweeping the gate voltage suggest that the effect is electrical rather than self-heating. We attribute the gating to an electric-field effect on the commensurate charge-density-wave domains in the atomic planes near the gate dielectric. The transition between the nearly commensurate and incommensurate charge-density-wave phases can be induced by both the source-drain current and the electrostatic gate. Since the charge-density-wave phases are persistent in 1T-TaS2 at room temperature, one can envision memory applications of such devices when scaled down to the dimensions of individual commensurate domains and few-atomic plane thicknesses.
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Affiliation(s)
- Maedeh Taheri
- Nano-Device Laboratory, Department of Electrical and Computer Engineering, Bourns College of Engineering, University of California, Riverside, California 92521, United States
| | - Jonas Brown
- Nano-Device Laboratory, Department of Electrical and Computer Engineering, Bourns College of Engineering, University of California, Riverside, California 92521, United States
| | - Adil Rehman
- CENTERA Laboratories, Institute of High-Pressure Physics, Polish Academy of Sciences, Warsaw 01-142, Poland
| | - Nicholas Sesing
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Fariborz Kargar
- Nano-Device Laboratory, Department of Electrical and Computer Engineering, Bourns College of Engineering, University of California, Riverside, California 92521, United States
- Phonon Optimized Engineered Materials Center, Materials Science and Engineering Program, Bourns College of Engineering, University of California, Riverside, California 92521, United States
| | - Tina T Salguero
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Sergey Rumyantsev
- CENTERA Laboratories, Institute of High-Pressure Physics, Polish Academy of Sciences, Warsaw 01-142, Poland
| | - Alexander A Balandin
- Nano-Device Laboratory, Department of Electrical and Computer Engineering, Bourns College of Engineering, University of California, Riverside, California 92521, United States
- Phonon Optimized Engineered Materials Center, Materials Science and Engineering Program, Bourns College of Engineering, University of California, Riverside, California 92521, United States
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17
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Kim D, Shin EC, Lee Y, Lee YH, Zhao M, Kim YH, Yang H. Atomic-scale thermopower in charge density wave states. Nat Commun 2022; 13:4516. [PMID: 35922417 PMCID: PMC9349257 DOI: 10.1038/s41467-022-32226-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 07/21/2022] [Indexed: 11/09/2022] Open
Abstract
The microscopic origins of thermopower have been investigated to design efficient thermoelectric devices, but strongly correlated quantum states such as charge density waves and Mott insulating phase remain to be explored for atomic-scale thermopower engineering. Here, we report on thermopower and phonon puddles in the charge density wave states in 1T-TaS2, probed by scanning thermoelectric microscopy. The Star-of-David clusters of atoms in 1T-TaS2 exhibit counterintuitive variations in thermopower with broken three-fold symmetry at the atomic scale, originating from the localized nature of valence electrons and their interlayer coupling in the Mott insulating charge density waves phase of 1T-TaS2. Additionally, phonon puddles are observed with a spatial range shorter than the conventional mean free path of phonons, revealing the phonon propagation and scattering in the subsurface structures of 1T-TaS2.
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Affiliation(s)
- Dohyun Kim
- Department of Energy Science, Sungkyunkwan University, Suwon, Korea
| | - Eui-Cheol Shin
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea
| | - Yongjoon Lee
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea
| | - Young Hee Lee
- Department of Energy Science, Sungkyunkwan University, Suwon, Korea.,Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science, Suwon, Korea
| | - Mali Zhao
- Interdisciplinary Materials Research Center, College of Materials Science and Engineering, Tongji University, Shanghai, People's Republic of China.
| | - Yong-Hyun Kim
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea.
| | - Heejun Yang
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea.
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18
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Gao FY, Zhang Z, Sun Z, Ye L, Cheng YH, Liu ZJ, Checkelsky JG, Baldini E, Nelson KA. Snapshots of a light-induced metastable hidden phase driven by the collapse of charge order. SCIENCE ADVANCES 2022; 8:eabp9076. [PMID: 35867789 PMCID: PMC9307249 DOI: 10.1126/sciadv.abp9076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 06/09/2022] [Indexed: 06/15/2023]
Abstract
Nonequilibrium hidden states provide a unique window into thermally inaccessible regimes of strong coupling between microscopic degrees of freedom in quantum materials. Understanding the origin of these states allows the exploration of far-from-equilibrium thermodynamics and the development of optoelectronic devices with on-demand photoresponses. However, mapping the ultrafast formation of a long-lived hidden phase remains a longstanding challenge since the initial state is not recovered rapidly. Here, using state-of-the-art single-shot spectroscopy techniques, we present a direct ultrafast visualization of the photoinduced phase transition to both transient and long-lived hidden states in an electronic crystal, 1T-TaS2, and demonstrate a commonality in their microscopic pathways, driven by the collapse of charge order. We present a theory of fluctuation-dominated process that helps explain the nature of the metastable state. Our results shed light on the origin of this elusive state and pave the way for the discovery of other exotic phases of matter.
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Affiliation(s)
- Frank Y. Gao
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Zhuquan Zhang
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Zhiyuan Sun
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Linda Ye
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Yu-Hsiang Cheng
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Zi-Jie Liu
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Joseph G. Checkelsky
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Edoardo Baldini
- Department of Physics, The University of Texas at Austin, Austin, TX 78712, USA
| | - Keith A. Nelson
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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19
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Petocchi F, Nicholson CW, Salzmann B, Pasquier D, Yazyev OV, Monney C, Werner P. Mott versus Hybridization Gap in the Low-Temperature Phase of 1T-TaS_{2}. PHYSICAL REVIEW LETTERS 2022; 129:016402. [PMID: 35841569 DOI: 10.1103/physrevlett.129.016402] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 04/07/2022] [Accepted: 06/01/2022] [Indexed: 06/15/2023]
Abstract
We address the long-standing problem of the ground state of 1T-TaS_{2} by computing the correlated electronic structure of stacked bilayers using the GW+EDMFT method. Depending on the surface termination, the semi-infinite uncorrelated system is either band insulating or exhibits a metallic surface state. For realistic values of the on-site and inter-site interactions, a Mott gap opens in the surface state, but it is smaller than the gap originating from the bilayer structure. Our results are consistent with recent scanning tunneling spectroscopy measurements for different terminating layers, and with our own photoemission measurements, which indicate the coexistence of spatial regions with different gaps in the electronic spectrum. By comparison to exact diagonalization data, we clarify the interplay between Mott insulating and band insulating behavior in this archetypal layered system.
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Affiliation(s)
- Francesco Petocchi
- Department of Physics, University of Fribourg, 1700 Fribourg, Switzerland
| | - Christopher W Nicholson
- Department of Physics, University of Fribourg, 1700 Fribourg, Switzerland
- Fritz-Haber-Institute der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - Bjoern Salzmann
- Department of Physics, University of Fribourg, 1700 Fribourg, Switzerland
| | - Diego Pasquier
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Oleg V Yazyev
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Claude Monney
- Department of Physics, University of Fribourg, 1700 Fribourg, Switzerland
| | - Philipp Werner
- Department of Physics, University of Fribourg, 1700 Fribourg, Switzerland
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20
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Mraz A, Venturini R, Svetin D, Sever V, Mihailovic IA, Vaskivskyi I, Ambrozic B, Dražić G, D’Antuono M, Stornaiuolo D, Tafuri F, Kazazis D, Ravnik J, Ekinci Y, Mihailovic D. Charge Configuration Memory Devices: Energy Efficiency and Switching Speed. NANO LETTERS 2022; 22:4814-4821. [PMID: 35688423 PMCID: PMC9228410 DOI: 10.1021/acs.nanolett.2c01116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/27/2022] [Indexed: 06/15/2023]
Abstract
Current trends in data processing have given impetus for an intense search of new concepts of memory devices with emphasis on efficiency, speed, and scalability. A promising new approach to memory storage is based on resistance switching between charge-ordered domain states in the layered dichalcogenide 1T-TaS2. Here we investigate the energy efficiency scaling of such charge configuration memory (CCM) devices as a function of device size and data write time τW as well as other parameters that have bearing on efficient device operation. We find that switching energy efficiency scales approximately linearly with both quantities over multiple decades, departing from linearity only when τW approaches the ∼0.5 ps intrinsic switching limit. Compared to current state of the art memory devices, CCM devices are found to be much faster and significantly more energy efficient, demonstrated here with two-terminal switching using 2.2 fJ, 16 ps electrical pulses.
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Affiliation(s)
- Anze Mraz
- Complex
Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
- Faculty
of Electrical Engineering, University of
Ljubljana, Tržaška
cesta 25, 1000 Ljubljana, Slovenia
| | - Rok Venturini
- Complex
Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
- Faculty
of Mathematics and Physics, University of
Ljubljana, Jadranska
cesta 19, 1000 Ljubljana, Slovenia
| | - Damjan Svetin
- Complex
Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
- CENN
Nanocenter, Jamova cesta
39, 1000 Ljubljana, Slovenia
| | - Vitomir Sever
- Complex
Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
| | | | - Igor Vaskivskyi
- Complex
Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
| | - Bojan Ambrozic
- CENN
Nanocenter, Jamova cesta
39, 1000 Ljubljana, Slovenia
| | - Goran Dražić
- Jozef
Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana, Slovenia
- Department
of Materials Chemistry, National Institute
of Chemistry, Hajdrihova
19, 1000 Ljubljana, Slovenia
| | - Maria D’Antuono
- Dipartimento
di Fisica “Ettore Pancini”, Università di Napoli Federico II, Monte S. Angelo via Cinthia, 80126 Napoli, Italy
- CNR-SPIN,
Complesso Monte Sant’Angelo, Via Cinthia, 80126 Napoli, Italy
| | - Daniela Stornaiuolo
- Dipartimento
di Fisica “Ettore Pancini”, Università di Napoli Federico II, Monte S. Angelo via Cinthia, 80126 Napoli, Italy
- CNR-SPIN,
Complesso Monte Sant’Angelo, Via Cinthia, 80126 Napoli, Italy
| | - Francesco Tafuri
- Dipartimento
di Fisica “Ettore Pancini”, Università di Napoli Federico II, Monte S. Angelo via Cinthia, 80126 Napoli, Italy
- CNR-Istituto
Nazionale di Ottica (CNR-INO), Largo Enrico Fermi 6, 50125 Florence, Italy
| | - Dimitrios Kazazis
- Paul
Scherrer Institute, Forschungsstrasse 111, 5232 Villigen PSI, Switzerland
| | - Jan Ravnik
- Paul
Scherrer Institute, Forschungsstrasse 111, 5232 Villigen PSI, Switzerland
| | - Yasin Ekinci
- Paul
Scherrer Institute, Forschungsstrasse 111, 5232 Villigen PSI, Switzerland
| | - Dragan Mihailovic
- Complex
Matter Department F7, Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
- CENN
Nanocenter, Jamova cesta
39, 1000 Ljubljana, Slovenia
- Faculty
of Mathematics and Physics, University of
Ljubljana, Jadranska
cesta 19, 1000 Ljubljana, Slovenia
- Jozef
Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana, Slovenia
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21
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Electronic Dislocation Dynamics in Metastable Wigner Crystal States. Symmetry (Basel) 2022. [DOI: 10.3390/sym14050926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Metastable states appear in many areas of physics as a result of symmetry-breaking phase transitions. An important challenge is to understand the microscopic mechanisms which lead to the formation of the energy barrier separating a metastable state from the ground state. In this paper, we describe an experimental example of the hidden metastable domain state in 1T-TaS2, created by photoexcitation or carrier injection. The system is an example of a charge density wave superlattice in the Wigner crystal limit displaying discommensurations and domain formation when additional charge is injected either through contacts or by photoexcitation. The domain walls and their crossings in particular display interesting, topologically entangled structures, which have a crucial role in the metastability of the system. We model the properties of experimentally observed thermally activated dynamics of topologically protected defects—dislocations—whose annihilation dynamics can be observed experimentally by scanning tunnelling microscopy as emergent phenomena described by a doped Wigner crystal. The different dynamics of trivial and non-trivial topological defects are quite striking. Trivial defects appear to annihilate quite rapidly at low temperatures on the timescale of the experiments, while non-trivial defects annihilate rarely, if at all.
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22
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Ledneva AY, Chebanova GE, Artemkina SB, Lavrov AN. CRYSTALLINE AND NANOSTRUCTURED MATERIALS BASED ON TRANSITION METAL DICHALCOGENIDES: SYNTHESIS AND ELECTRONIC PROPERTIES. J STRUCT CHEM+ 2022. [DOI: 10.1134/s0022476622020020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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23
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Walker SM, Patel T, Okamoto J, Langenberg D, Bergeron EA, Gao J, Luo X, Lu W, Sun Y, Tsen AW, Baugh J. Observation and Manipulation of a Phase Separated State in a Charge Density Wave Material. NANO LETTERS 2022; 22:1929-1936. [PMID: 35176209 DOI: 10.1021/acs.nanolett.1c04514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The 1T polytype of TaS2 has been studied extensively as a strongly correlated system. As 1T-TaS2 is thinned toward the 2D limit, its phase diagram shows significant deviations from that of the bulk material. Optoelectronic maps of ultrathin 1T-TaS2 have indicated the presence of nonequilibrium charge density wave phases within the hysteresis region of the nearly commensurate (NC) to commensurate (C) transition. We perform scanning tunneling microscopy on exfoliated ultrathin flakes of 1T-TaS2 within the NC-C hysteresis window, finding evidence that the observed nonequilibrium phases consist of intertwined, irregularly shaped NC-like and C-like domains. After applying lateral electrical signals to the sample, we image changes in the geometric arrangement of the different regions. We use a phase separation model to explore the relationship between electronic inhomogeneity present in ultrathin 1T-TaS2 and its bulk resistivity. These results demonstrate the role of phase competition morphologies in determining the properties of 2D materials.
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Affiliation(s)
- Sean M Walker
- Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Tarun Patel
- Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- Department of Physics, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Junichi Okamoto
- Institute of Physics, University of Freiburg, D-79104 Freiburg, Germany
- EUCOR Centre for Quantum Science and Quantum Computing, University of Freiburg, D-79104 Freiburg, Germany
| | - Deler Langenberg
- Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - E Annelise Bergeron
- Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- Department of Physics, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Jingjing Gao
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, 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
| | - Wenjian Lu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
| | - Yuping Sun
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
- Collaborative Innovation Centre of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Adam W Tsen
- Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Jonathan Baugh
- Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
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24
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Huang Z, Song X, Chen Y, Yang H, Yuan P, Ma H, Qiao J, Zhang Y, Sun J, Zhang T, Huang Y, Liu L, Gao HJ, Wang Y. Size Dependence of Charge-Density-Wave Orders in Single-Layer NbSe 2 Hetero/Homophase Junctions. J Phys Chem Lett 2022; 13:1901-1907. [PMID: 35179388 DOI: 10.1021/acs.jpclett.1c04138] [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
Controlling charge-density-wave (CDW) orders in two-dimensional (2D) crystals has attracted a great deal of interest because of their fundamental physics and their demand inse in miniaturized devices. In this work, we systematically studied the size-dependent CDW orders in single-layer hetero/homo-NbSe2 stacking junctions. We found that the CDW orders in the top 1T-NbSe2 layer of the junctions are highly dependent on its lateral size. For the 1T/2H-NbSe2 heterojunction, the critical lateral size of 1T-NbSe2 islands for the formation of well-defined CDW orders is ∼26 nm, whereas below 15 nm, the CDW orders melt. However, for the 1T/1T-NbSe2 homojunction, the CDW orders in the islands can persist even with a lateral size of <11 nm. Our findings illuminate the fresh phenomenon of size-dependent CDW orders existing in 2D van der Waals hetero/homojunctions and provide useful information for the control of CDW orders.
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Affiliation(s)
- Zeping Huang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Xuan Song
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Yaoyao Chen
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Han Yang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Peiwen Yuan
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Hang Ma
- School of Automation, Beijing Information Science and Technology University, Beijing 100085, China
| | - Jingsi Qiao
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
- Centre for Advanced 2D Materials, National University of Singapore, 117546 Singapore
| | - Yu Zhang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Jiatao Sun
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Teng Zhang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Yuan Huang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Liwei Liu
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Hong-Jun Gao
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yeliang Wang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
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25
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Sung SH, Schnitzer N, Novakov S, El Baggari I, Luo X, Gim J, Vu NM, Li Z, Brintlinger TH, Liu Y, Lu W, Sun Y, Deotare PB, Sun K, Zhao L, Kourkoutis LF, Heron JT, Hovden R. Two-dimensional charge order stabilized in clean polytype heterostructures. Nat Commun 2022; 13:413. [PMID: 35058434 PMCID: PMC8776735 DOI: 10.1038/s41467-021-27947-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 11/18/2021] [Indexed: 11/23/2022] Open
Abstract
Compelling evidence suggests distinct correlated electron behavior may exist only in clean 2D materials such as 1T-TaS2. Unfortunately, experiment and theory suggest that extrinsic disorder in free standing 2D layers disrupts correlation-driven quantum behavior. Here we demonstrate a route to realizing fragile 2D quantum states through endotaxial polytype engineering of van der Waals materials. The true isolation of 2D charge density waves (CDWs) between metallic layers stabilizes commensurate long-range order and lifts the coupling between neighboring CDW layers to restore mirror symmetries via interlayer CDW twinning. The twinned-commensurate charge density wave (tC-CDW) reported herein has a single metal-insulator phase transition at ~350 K as measured structurally and electronically. Fast in-situ transmission electron microscopy and scanned nanobeam diffraction map the formation of tC-CDWs. This work introduces endotaxial polytype engineering of van der Waals materials to access latent 2D ground states distinct from conventional 2D fabrication.
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Affiliation(s)
- Suk Hyun Sung
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Noah Schnitzer
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, 14853, USA
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, NY, 14853, USA
| | - Steve Novakov
- Department of Physics, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Ismail El Baggari
- Department of Physics, Cornell University, Ithaca, NY, 14853, USA
- Rowland Institute at Harvard, Cambridge, MA, 02142, USA
| | - Xiangpeng Luo
- Department of Physics, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Jiseok Gim
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Nguyen M Vu
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Zidong Li
- Electrical and Computer Engineering Department, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Todd H Brintlinger
- Materials Science and Technology Division, U.S. Naval Research Laboratory, Washington, D.C., 20375, USA
| | - Yu Liu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, 230031, Hefei, P. R. China
| | - Wenjian Lu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, 230031, Hefei, P. R. China
| | - Yuping Sun
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, 230031, Hefei, P. R. China
- High Magnetic Field Laboratory, Chinese Academy of Sciences, 230031, Hefei, P. R. China
- Collaborative Innovation Centre of Advanced Microstructures, Nanjing University, 210093, Nanjing, P. R. China
| | - Parag B Deotare
- Electrical and Computer Engineering Department, University of Michigan, Ann Arbor, MI, 48109, USA
- Applied Physics Program, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Kai Sun
- Department of Physics, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Liuyan Zhao
- Department of Physics, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Lena F Kourkoutis
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, NY, 14853, USA
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, 14853, USA
| | - John T Heron
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
- Applied Physics Program, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Robert Hovden
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, 48109, USA.
- Applied Physics Program, University of Michigan, Ann Arbor, MI, 48109, USA.
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26
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Yao Q, Park JW, Oh E, Yeom HW. Engineering Domain Wall Electronic States in Strongly Correlated van der Waals Material of 1T-TaS 2. NANO LETTERS 2021; 21:9699-9705. [PMID: 34738815 DOI: 10.1021/acs.nanolett.1c03522] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Although a few physical methods were demonstrated for domain wall engineering in various electronic or ferroic materials with broken discrete symmetries, the direct control over the electronic properties of individual domain walls has been extremely limited. Here, we introduce a chemical method to tune the electronic property of domain walls in 1T tantalum disulfide. By using scanning tunneling microscopy and spectroscopy techniques, we find that indium adatoms on 1T-TaS2 have distinct behaviors on the domains with different bulk terminations. Moreover, the adatoms form their own chains along the edges of neighboring domains. The density functional theory calculations reveal a 1D Mott insulating state on a modified domain wall, resulting from the degenerated spin-polarized bands with electron doping from adsorbates and charge transfer from neighboring domains. This work suggests that chemical decoration by adsorbates can be widely used to tune local electronic states of domain walls and various 2D materials.
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Affiliation(s)
- Qirong Yao
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
| | - Jae Whan Park
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
| | - Eunseok Oh
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Han Woong Yeom
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
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27
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Pathan MAK, Gupta A, Vaida ME. Exploring the growth and oxidation of 2D-TaS 2on Cu(111). NANOTECHNOLOGY 2021; 32:505605. [PMID: 34492643 DOI: 10.1088/1361-6528/ac244e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 09/07/2021] [Indexed: 06/13/2023]
Abstract
In this work, the growth and stability towards O2exposure of two dimensional (2D) TaS2on a Cu(111) substrate is investigated. Large area (∼1 cm2) crystalline 2D-TaS2films with a metallic character are prepared on a single crystal Cu(111) substrate via a multistep approach based on physical vapor deposition. Analytical techniques such as Auger electron spectroscopy, low energy electron diffraction, and photoemission spectroscopy are used to characterize the composition, crystallinity, and electronic structure of the surface. At coverages below one monolayer equivalent (ML), misoriented TaS2domains are formed, which are rotated up to±13orelative to the Cu(111) crystallographic directions. The TaS2domains misorientation decreases as the film thickness approaches 1 ML, at which the crystallographic directions of TaS2and Cu(111) are aligned. The TaS2film is found to grow epitaxially on Cu(111). As revealed by low energy electron diffraction in conjunction with an atomic model simulation, the (3 × 3) unit cells of TaS2match the (4 × 4) supercell of Cu(111). Furthermore, the exposure of TaS2to O2, does not lead to the formation of a robust tantalum oxide film, only minor amounts of stable oxides being detected on the surface. Instead, the exposure of TaS2films to O2leads predominantly to a reduction of the film thickness, evidenced by a decrease in the content of both Ta and S atoms of the film. This is attributed to the formation of oxide species that are unstable and mainly desorb from the surface below room temperature. Temperature programmed desorption spectroscopy confirms the formation of SO2, which desorbs from the surface between 100 and500 K.These results provide new insights into the oxidative degradation of 2D-TaS2on Cu(111).
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Affiliation(s)
- Md Afjal Khan Pathan
- Department of Physics, University of Central Florida, Orlando, FL 32816, United States of America
| | - Aakash Gupta
- Department of Physics, University of Central Florida, Orlando, FL 32816, United States of America
| | - Mihai E Vaida
- Department of Physics, University of Central Florida, Orlando, FL 32816, United States of America
- Renewable Energy and Chemical Transformation Cluster, University of Central Florida, Orlando, FL 32816, United States of America
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28
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Micromask Lithography for Cheap and Fast 2D Materials Microstructures Fabrication. MICROMACHINES 2021; 12:mi12080850. [PMID: 34442473 PMCID: PMC8397995 DOI: 10.3390/mi12080850] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/15/2021] [Accepted: 07/19/2021] [Indexed: 12/17/2022]
Abstract
The fast and precise fabrication of micro-devices based on single flakes of novel 2D materials and stacked heterostructures is vital for exploration of novel functionalities. In this paper, we demonstrate a fast high-resolution contact mask lithography through a simple upgrade of metallographic optical microscope. Suggested kit for the micromask lithography is compact and easily compatible with a glove box, thus being suitable for a wide range of air-unstable materials. The shadow masks could be either ordered commercially or fabricated in a laboratory using a beam lithography. The processes of the mask alignment and the resist exposure take a few minutes and provide a micrometer resolution. With the total price of the kit components around USD 200, our approach would be convenient for laboratories with the limited access to commercial lithographic systems.
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29
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Sood A, Shen X, Shi Y, Kumar S, Park SJ, Zajac M, Sun Y, Chen LQ, Ramanathan S, Wang X, Chueh WC, Lindenberg AM. Universal phase dynamics in VO 2 switches revealed by ultrafast operando diffraction. Science 2021; 373:352-355. [PMID: 34437156 DOI: 10.1126/science.abc0652] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 06/07/2021] [Indexed: 11/02/2022]
Abstract
Understanding the pathways and time scales underlying electrically driven insulator-metal transitions is crucial for uncovering the fundamental limits of device operation. Using stroboscopic electron diffraction, we perform synchronized time-resolved measurements of atomic motions and electronic transport in operating vanadium dioxide (VO2) switches. We discover an electrically triggered, isostructural state that forms transiently on microsecond time scales, which is shown by phase-field simulations to be stabilized by local heterogeneities and interfacial interactions between the equilibrium phases. This metastable phase is similar to that formed under photoexcitation within picoseconds, suggesting a universal transformation pathway. Our results establish electrical excitation as a route for uncovering nonequilibrium and metastable phases in correlated materials, opening avenues for engineering dynamical behavior in nanoelectronics.
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Affiliation(s)
- Aditya Sood
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA. .,Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Xiaozhe Shen
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Yin Shi
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Suhas Kumar
- Hewlett Packard Labs, Palo Alto, CA 94304, USA
| | - Su Ji Park
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Marc Zajac
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Yifei Sun
- School of Materials Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Long-Qing Chen
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Shriram Ramanathan
- School of Materials Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Xijie Wang
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - William C Chueh
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA.,Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Aaron M Lindenberg
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA. .,Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA.,SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
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30
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Reisbick SA, Zhang Y, Chen J, Engen PE, Flannigan DJ. Coherent Phonon Disruption and Lock-In during a Photoinduced Charge-Density-Wave Phase Transition. J Phys Chem Lett 2021; 12:6439-6447. [PMID: 34236194 DOI: 10.1021/acs.jpclett.1c01673] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Ultrafast manipulation of phase domains in quantum materials is a promising approach to unraveling and harnessing interwoven charge and lattice degrees of freedom. Here we find evidence for coupling of displacively excited coherent acoustic phonons (CAPs) and periodic lattice distortions (PLDs) in the intensely studied charge-density-wave material, 1T-TaS2, using 4D ultrafast electron microscopy (UEM). Initial photoinduced Bragg-peak dynamics reveal partial CAP coherence and localized c-axis dilations. Weak, partially coherent dynamics give way to higher-amplitude, increasingly coherent oscillations, the transition period of which matches that of photoinduced incommensurate domain growth and stabilization from the nearly-commensurate phase. With UEM imaging, it is found that phonon wave trains emerge from linear defects 100 ps after photoexcitation. The CAPs consist of coupled longitudinal and transverse character and propagate at anomalously high velocities along wave vectors independent from PLDs, instead being dictated by defect orientation. Such behaviors illustrate a means to control phases in quantum materials using defect-engineered coherent-phonon seeding.
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Affiliation(s)
- Spencer A Reisbick
- Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455, United States
| | - Yichao Zhang
- Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455, United States
| | - Jialiang Chen
- Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455, United States
| | - Paige E Engen
- Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455, United States
| | - David J Flannigan
- Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455, United States
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31
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Femtosecond control of phonon dynamics near a magnetic order critical point. Nat Commun 2021; 12:2865. [PMID: 34001880 PMCID: PMC8129429 DOI: 10.1038/s41467-021-23059-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 04/13/2021] [Indexed: 11/21/2022] Open
Abstract
The spin-phonon interaction in spin density wave (SDW) systems often determines the free energy landscape that drives the evolution of the system. When a passing energy flux, such as photoexcitation, drives a crystalline system far from equilibrium, the resulting lattice displacement generates transient vibrational states. Manipulating intermediate vibrational states in the vicinity of the critical point, where the SDW order parameter changes dramatically, would then allow dynamical control over functional properties. Here we combine double photoexcitation with an X-ray free-electron laser (XFEL) probe to control and detect the lifetime and magnitude of the intermediate vibrational state near the critical point of the SDW in chromium. We apply Landau theory to identify the mechanism of control as a repeated partial quench and sub picosecond recovery of the SDW. Our results showcase the capabilities to influence and monitor quantum states by combining multiple optical photoexcitations with an XFEL probe. They open new avenues for manipulating and researching the behaviour of photoexcited states in charge and spin order systems near the critical point. Precise control of vibrational states coupled to electronic degrees of freedom could enable control over charge or magnetic order in a material. Here, the authors use a double-pulse photoexcitation combined with an X-ray probe to control vibrational states near the critical point of spin density wave in Cr films.
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32
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Ravnik J, Diego M, Gerasimenko Y, Vaskivskyi Y, Vaskivskyi I, Mertelj T, Vodeb J, Mihailovic D. A time-domain phase diagram of metastable states in a charge ordered quantum material. Nat Commun 2021; 12:2323. [PMID: 33875669 PMCID: PMC8055663 DOI: 10.1038/s41467-021-22646-7] [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: 11/02/2020] [Accepted: 03/17/2021] [Indexed: 11/11/2022] Open
Abstract
Metastable self-organized electronic states in quantum materials are of fundamental importance, displaying emergent dynamical properties that may be used in new generations of sensors and memory devices. Such states are typically formed through phase transitions under non-equilibrium conditions and the final state is reached through processes that span a large range of timescales. Conventionally, phase diagrams of materials are thought of as static, without temporal evolution. However, many functional properties of materials arise as a result of complex temporal changes in the material occurring on different timescales. Hitherto, such properties were not considered within the context of a temporally-evolving phase diagram, even though, under non-equilibrium conditions, different phases typically evolve on different timescales. Here, by using time-resolved optical techniques and femtosecond-pulse-excited scanning tunneling microscopy (STM), we track the evolution of the metastable states in a material that has been of wide recent interest, the quasi-two-dimensional dichalcogenide 1T-TaS2. We map out its temporal phase diagram using the photon density and temperature as control parameters on timescales ranging from 10−12 to 103 s. The introduction of a time-domain axis in the phase diagram enables us to follow the evolution of metastable emergent states created by different phase transition mechanisms on different timescales, thus enabling comparison with theoretical predictions of the phase diagram, and opening the way to understanding of the complex ordering processes in metastable materials. Tracking the evolution of non-equilibrium phases requires measurements over a wide range of timescales. Here, using a combination of femtosecond spectroscopy and scanning tunneling microscopy, the authors map out a temporal phase diagram of metastable states in a charge-ordered material 1T-TaS2.
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Affiliation(s)
- Jan Ravnik
- Complex Matter Department, Jozef Stefan Institute, Ljubljana, Slovenia.,Laboratory for Micro and Nanotechnology, Paul Scherrer Institut, Villigen PSI, Switzerland
| | - Michele Diego
- Complex Matter Department, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Yaroslav Gerasimenko
- Complex Matter Department, Jozef Stefan Institute, Ljubljana, Slovenia.,Center of Excellence on Nanoscience and Nanotechnology-Nanocenter (CENN Nanocenter), Ljubljana, Slovenia
| | | | - Igor Vaskivskyi
- Complex Matter Department, Jozef Stefan Institute, Ljubljana, Slovenia.,Center of Excellence on Nanoscience and Nanotechnology-Nanocenter (CENN Nanocenter), Ljubljana, Slovenia
| | - Tomaz Mertelj
- Complex Matter Department, Jozef Stefan Institute, Ljubljana, Slovenia.,Center of Excellence on Nanoscience and Nanotechnology-Nanocenter (CENN Nanocenter), Ljubljana, Slovenia
| | - Jaka Vodeb
- Complex Matter Department, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Dragan Mihailovic
- Complex Matter Department, Jozef Stefan Institute, Ljubljana, Slovenia. .,Center of Excellence on Nanoscience and Nanotechnology-Nanocenter (CENN Nanocenter), Ljubljana, Slovenia. .,Department of Physics, Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana, Slovenia.
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33
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Zhang Q, Huang Z, Hou Y, Yuan P, Xu Z, Yang H, Song X, Chen Y, Yang H, Zhang T, Liu L, Gao HJ, Wang Y. Tuning Molecular Superlattice by Charge-Density-Wave Patterns in Two-Dimensional Monolayer Crystals. J Phys Chem Lett 2021; 12:3545-3551. [PMID: 33818110 DOI: 10.1021/acs.jpclett.1c00230] [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
Charge density wave (CDW) in two-dimensional (2D) crystals plays a vital role in tuning the interface structures and properties. However, how the CDW tunes the self-assembled molecular superlattice still remains unclear. In this study, we investigated the self-assembled manganese phthalocyanine (MnPc) molecular superlattice on single-layered 1T- and 2H-NbSe2 crystals under regulation by distinct CDW patterns. We observe that, in low coverage, MnPc molecules preferentially adsorb on 2H-NbSe2 compared to 1T-NbSe2. With increasing coverage, MnPc can form a highly ordered superlattice on 2H-NbSe2; however, it is randomly distributed on 1T-NbSe2. We reveal a perfect geometric commensurability between the molecular superlattice and intrinsic CDW pattern in 2H-NbSe2 and a poor commensurability for that of 1T-NbSe2. We believe that the subtly different geometric commensurability dominates the different adsorption and arrangement of the molecular superlattices on 2D CDW patterns. Our study provides a pioneering approach for tuning the molecular superlattices using the CDW patterns.
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Affiliation(s)
- Quanzhen Zhang
- MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China
| | - Zeping Huang
- MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China
| | - Yanhui Hou
- MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China
| | - Peiwen Yuan
- MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China
| | - Ziqiang Xu
- MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China
| | - Han Yang
- MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China
| | - Xuan Song
- MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China
| | - Yaoyao Chen
- MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China
| | - Huixia Yang
- MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China
| | - Teng Zhang
- MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China
| | - Liwei Liu
- MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China
| | - Hong-Jun Gao
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yeliang Wang
- MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China
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34
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Liu L, Yang H, Huang Y, Song X, Zhang Q, Huang Z, Hou Y, Chen Y, Xu Z, Zhang T, Wu X, Sun J, Huang Y, Zheng F, Li X, Yao Y, Gao HJ, Wang Y. Direct identification of Mott Hubbard band pattern beyond charge density wave superlattice in monolayer 1T-NbSe 2. Nat Commun 2021; 12:1978. [PMID: 33785747 PMCID: PMC8010100 DOI: 10.1038/s41467-021-22233-w] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 03/03/2021] [Indexed: 11/22/2022] Open
Abstract
Understanding Mott insulators and charge density waves (CDW) is critical for both fundamental physics and future device applications. However, the relationship between these two phenomena remains unclear, particularly in systems close to two-dimensional (2D) limit. In this study, we utilize scanning tunneling microscopy/spectroscopy to investigate monolayer 1T-NbSe2 to elucidate the energy of the Mott upper Hubbard band (UHB), and reveal that the spin-polarized UHB is spatially distributed away from the dz2 orbital at the center of the CDW unit. Moreover, the UHB shows a √3 × √3 R30° periodicity in addition to the typically observed CDW pattern. Furthermore, a pattern similar to the CDW order is visible deep in the Mott gap, exhibiting CDW without contribution of the Mott Hubbard band. Based on these findings in monolayer 1T-NbSe2, we provide novel insights into the relation between the correlated and collective electronic structures in monolayer 2D systems.
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Affiliation(s)
- Liwei Liu
- School of Information and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, China.
| | - Han Yang
- School of Information and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, China
| | - Yuting Huang
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, China
| | - Xuan Song
- School of Information and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, China
| | - Quanzhen Zhang
- School of Information and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, China
| | - Zeping Huang
- School of Information and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, China
| | - Yanhui Hou
- School of Information and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, China
| | - Yaoyao Chen
- School of Information and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, China
| | - Ziqiang Xu
- School of Information and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, China
| | - Teng Zhang
- School of Information and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, China
| | - Xu Wu
- School of Information and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, China
| | - Jiatao Sun
- School of Information and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, China
| | - Yuan Huang
- School of Information and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, China
- Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Fawei Zheng
- Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement (MOE) and School of Physics, Beijing Institute of Technology, Beijing, China
| | - Xianbin Li
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, China
| | - Yugui Yao
- Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement (MOE) and School of Physics, Beijing Institute of Technology, Beijing, China
| | - Hong-Jun Gao
- Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Yeliang Wang
- School of Information and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing, China
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35
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Prosandeev S, Grollier J, Talbayev D, Dkhil B, Bellaiche L. Ultrafast Neuromorphic Dynamics Using Hidden Phases in the Prototype of Relaxor Ferroelectrics. PHYSICAL REVIEW LETTERS 2021; 126:027602. [PMID: 33512197 DOI: 10.1103/physrevlett.126.027602] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 12/18/2020] [Indexed: 06/12/2023]
Abstract
Materials possessing multiple states are promising to emulate synaptic and neuronic behaviors. Their operation frequency, typically in or below the GHz range, however, limits the speed of neuromorphic computing. Ultrafast THz electric field excitation has been employed to induce nonequilibrium states of matter, called hidden phases in oxides. One may wonder if there are systems for which THz pulses can generate neuronic and synaptic behavior, via the creation of hidden phases. Using atomistic simulations, we discover that relaxor ferroelectrics can emulate all the key neuronic and memristive synaptic features. Their occurrence originates from the activation of many hidden phases of polarization order, resulting from the response of nanoregions to THz pulses. Such phases further possess different dielectric constants, which is also promising for memcapacitor devices.
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Affiliation(s)
- Sergey Prosandeev
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - Julie Grollier
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
| | - Diyar Talbayev
- Department of Physics and Engineering Physics, Tulane University, 6400 Freret Street, New Orleans, Louisiana 70118, USA
| | - Brahim Dkhil
- Laboratoire Structures, Propriétés et Modélisation des Solides, CentraleSupelec, Université Paris-Saclay, CNRS-UMR8580, 91190 Gif-sur-Yvette, France
| | - L Bellaiche
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA
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36
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Hossain M, Iqbal MA, Wu J, Xie L. Chemical vapor deposition and temperature-dependent Raman characterization of two-dimensional vanadium ditelluride. RSC Adv 2021; 11:2624-2629. [PMID: 35424251 PMCID: PMC8693834 DOI: 10.1039/d0ra07868a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 12/22/2020] [Indexed: 11/21/2022] Open
Abstract
Recently, ultrathin two-dimensional (2D) metallic vanadium dichalcogenides have attracted widespread attention because of the charge density wave (CDW) phase transition and possible ferromagnetism. Herein, we report the synthesis and temperature-dependent Raman characterization of the 2D vanadium ditelluride (VTe2). The synthesis is done by atmospheric pressure chemical vapor deposition (APCVD) using vanadium chloride (VCl3) precursor on fluorphlogopite mica, sapphire, and h-BN substrates. A large area of the thin film with thickness ∼10 nm is grown on the hexagonal boron nitride (h-BN) substrate. Temperature-dependent Raman characterization of VTe2 is conducted from room temperature to 513 K. Remarkable changes of Raman modes at around 413 K are observed, indicating the structural phase transition. Two-dimensional vanadium ditelluride has been synthesized on mica, sapphire, and h-BN substrates by atmospheric pressure chemical vapor deposition.![]()
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Affiliation(s)
- Mongur Hossain
- Hunan Key Laboratory of Two-Dimensional Materials, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University Changsha 410082 P. R. China .,CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology Beijing 100190 P. R. China .,University of Chinese Academy of Sciences Beijing 100049 P. R. China
| | - Muhammad Ahsan Iqbal
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology Beijing 100190 P. R. China .,University of Chinese Academy of Sciences Beijing 100049 P. R. China
| | - Juanxia Wu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology Beijing 100190 P. R. China
| | - Liming Xie
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology Beijing 100190 P. R. China .,University of Chinese Academy of Sciences Beijing 100049 P. R. China
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37
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Patel T, Okamoto J, Dekker T, Yang B, Gao J, Luo X, Lu W, Sun Y, Tsen AW. Photocurrent Imaging of Multi-Memristive Charge Density Wave Switching in Two-Dimensional 1T-TaS 2. NANO LETTERS 2020; 20:7200-7206. [PMID: 32960610 DOI: 10.1021/acs.nanolett.0c02537] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Transport studies of atomically thin 1T-TaS2 have demonstrated the presence of intermediate resistance states across the nearly commensurate (NC) to commensurate (C) charge density wave (CDW) transition, which can be further switched electrically. While this presents exciting opportunities for memristor applications, the switching mechanism could be potentially attributed to the formation of inhomogeneous C and NC domains. Here, we present combined electrical driving and photocurrent imaging of ultrathin 1T-TaS2 in a heterostructure geometry. While micron-sized CDW domains are seen upon cooling, electrically driven transitions are largely uniform, indicating that the latter likely induces true metastable CDW states, which we then explain by a free energy analysis. Additionally, we are able to perform repeatable and bidirectional switching across the intermediate states without changing sample temperature, demonstrating that atomically thin 1T-TaS2 can be further used as a robust and reversible multimemristor material for the first time.
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Affiliation(s)
- Tarun Patel
- Institute for Quantum Computing, Department of Physics and Astronomy, Department of Electrical and Computer Engineering, and Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Junichi Okamoto
- Institute of Physics, University of Freiburg, D-79104 Freiburg, Germany
| | - Tina Dekker
- Institute for Quantum Computing, Department of Physics and Astronomy, Department of Electrical and Computer Engineering, and Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Bowen Yang
- Institute for Quantum Computing, Department of Physics and Astronomy, Department of Electrical and Computer Engineering, and Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Jingjing Gao
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
- University of Science and Technology of China, Hefei 230026, 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
| | - Wenjian Lu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
| | - Yuping Sun
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
- Collaborative Innovation Centre of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Adam W Tsen
- Institute for Quantum Computing, Department of Physics and Astronomy, Department of Electrical and Computer Engineering, and Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
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38
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Dang C, Guan M, Hussain S, Wen W, Zhu Y, Jiao L, Meng S, Xie L. Phase Transition Photodetection in Charge Density Wave Tantalum Disulfide. NANO LETTERS 2020; 20:6725-6731. [PMID: 32787147 DOI: 10.1021/acs.nanolett.0c02613] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The charge density wave (CDW) phase is a macroscopic quantum state with periodic charge density modulation accompanied by periodic lattice distortion in low-dimensional metals. External fields, such as an electric field and optical excitation, can trigger the transitions among different CDW states, leaving an under-explored mechanism and attracting great interest toward optoelectronic applications. Here, we explore a photoinduced phase transition in 1T-TaS2 under an electrical field. By analyzing the phase transition probability, we obtained a linear dependence of the phase transition barrier on the electric field and laser energy density. Additionally, the threshold laser energy for the phase transition decreases linearly with an increasing applied electrical field. Finally, picojoule photodetection was realized in the visible and near-infrared ranges near the CDW transition edge. Our work will promote the understanding of the CDW phase transition mechanism as well as open pathways for optoelectronic applications.
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Affiliation(s)
- Chunhe Dang
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P.R. China
- University of Chinese Academy of Sciences, Beijing 100049, P.R. China
- Department of Chemistry, Tsinghua University, Beijing 100084, P.R. China
| | - Mengxue Guan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, P.R. China
| | - Sabir Hussain
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P.R. China
- University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Wen Wen
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P.R. China
- University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Yiming Zhu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P.R. China
| | - Liying Jiao
- Department of Chemistry, Tsinghua University, Beijing 100084, P.R. China
| | - Sheng Meng
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, P.R. China
| | - Liming Xie
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P.R. China
- University of Chinese Academy of Sciences, Beijing 100049, P.R. China
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39
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Gao J, Park JW, Kim K, Song SK, Park HR, Lee J, Park J, Chen F, Luo X, Sun Y, Yeom HW. Pseudogap and Weak Multifractality in 2D Disordered Mott Charge-Density-Wave Insulator. NANO LETTERS 2020; 20:6299-6305. [PMID: 32787162 DOI: 10.1021/acs.nanolett.0c01607] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We investigate electronic states of Se-substituted 1T-TaS2 by scanning tunneling microscopy/spectroscopy (STM/STS), where superconductivity emerges from the unique Mott-charge-density-wave (Mott-CDW) state. Spatially resolved STS measurements reveal that a pseudogap replaces the Mott gap with the CDW gaps intact. The pseudogap has little correlation with the unit-cell-to-unit-cell variation in the local Se concentration but appears globally. The correlation length of the local density of states (LDOS) is substantially enhanced at the Fermi energy and decays rapidly at high energies. Furthermore, the statistical analysis of LDOS indicates the weak multifractal behavior of the wave functions. These findings suggest a correlated metallic state induced by disorder and provide a new insight into the emerging superconductivity in two-dimensional materials.
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Affiliation(s)
- Jianhua Gao
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
| | - Jae Whan Park
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
| | - Kiseok Kim
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Sun Kyu Song
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Hae Ryong Park
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Jhinhwan Lee
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
| | - Jewook Park
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
| | - Fangchu Chen
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
- University of Science and Technology of China, Hefei 230026, 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
| | - Yuping Sun
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
- Collaborative Innovation Centre of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Han Woong Yeom
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
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40
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Chen K, Deng J, Shi Q, Ding X, Sun J, Yang S, Liu JZ. Charge doping induced reversible multistep structural phase transitions and electromechanical actuation in two-dimensional 1T'-MoS 2. NANOSCALE 2020; 12:12541-12550. [PMID: 32500127 DOI: 10.1039/d0nr02049d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The 1T' phase of transition metal dichalcogenides (TMDs) is a low symmetry charge density wave (CDW) phase, which can be viewed as a periodically distorted structure (Peierls distortion) of the high symmetry 1T phase. In this paper, using density functional theory (DFT) calculations, we report that the positive charge (hole) injection is an effective method to modulate the Peierls distortion of MoS2 1T' for a new CDW phase and superior electromechanical properties. A new stable CDW phase is discovered at a hole doping level of 0.10 h+ per atom, named 1T't. Hole charging and discharging can induce a reversible phase transition of MoS2 among the three phases, 1T, 1T' and 1T't. Such a reversible phase transition leads to superior electromechanical properties including a strain output as high as -5.8% with a small hysteresis loop, multi-step super-elasticity, and multi-shape memory effect, which are valuable in active electromechanical device designs at the nanoscale. In-depth analysis of the change of the electronic structure under hole doping was performed to understand the new CDW phase and the observed phase transition. Using charge doping to modulate the Peierls distortion in two-dimensional materials can serve as a general concept for nano-active material designs.
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Affiliation(s)
- Kaiyun Chen
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Junkai Deng
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Qian Shi
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Xiangdong Ding
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Jun Sun
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Sen Yang
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Jefferson Zhe Liu
- Department of Mechanical Engineering, The University of Melbourne, Parkville, VIC 3010, Australia.
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41
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Mottness versus unit-cell doubling as the driver of the insulating state in 1T-TaS 2. Nat Commun 2020; 11:2477. [PMID: 32424136 PMCID: PMC7235044 DOI: 10.1038/s41467-020-16132-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 04/14/2020] [Indexed: 11/08/2022] Open
Abstract
If a material with an odd number of electrons per unit-cell is insulating, Mott localisation may be invoked as an explanation. This is widely accepted for the layered compound 1T-TaS2, which has a low-temperature insulating phase comprising charge order clusters with 13 unpaired orbitals each. But if the stacking of layers doubles the unit-cell to include an even number of orbitals, the nature of the insulating state is ambiguous. Here, scanning tunnelling microscopy reveals two distinct terminations of the charge order in 1T-TaS2, the sign of such a double-layer stacking pattern. However, spectroscopy at both terminations allows us to disentangle unit-cell doubling effects and determine that Mott localisation alone can drive gap formation. We also observe the collapse of Mottness at an extrinsically re-stacked termination, demonstrating that the microscopic mechanism of insulator-metal transitions lies in degrees of freedom of inter-layer stacking. In many strongly correlated systems the coupling of electronic and lattice degrees of freedom leads to ambiguity over the mechanism driving electronic phase transitions. Here the authors show that inter-layer effects play an important role in the charge ordering transition of 1T-TaS2.
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42
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Zhu XY, Wang S, Jia ZY, Zhu L, Li QY, Zhao WM, Xue CL, Xu YJ, Ma Z, Wen J, Yu SL, Li JX, Li SC. Realization of a Metallic State in 1T-TaS_{2} with Persisting Long-Range Order of a Charge Density Wave. PHYSICAL REVIEW LETTERS 2019; 123:206405. [PMID: 31809103 DOI: 10.1103/physrevlett.123.206405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Indexed: 06/10/2023]
Abstract
Metallization of 1T-TaS_{2} is generally initiated at the domain boundary of a charge density wave (CDW), at the expense of its long-range order. However, we demonstrate in this study that the metallization of 1T-TaS_{2} can be also realized without breaking the long-range CDW order upon surface alkali doping. By using scanning tunneling microscopy, we find the long-range CDW order is always persisting, and the metallization is instead associated with additional in-gap excitations. Interestingly, the in-gap excitation is near the top of the lower Hubbard band, in contrast to a conventional electron-doped Mott insulator where it is beneath the upper Hubbard band. In combination with the numerical calculations, we suggest that the appearance of the in-gap excitations near the lower Hubbard band is mainly due to the effectively reduced on-site Coulomb energy by the adsorbed alkali ions.
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Affiliation(s)
- Xin-Yang Zhu
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
| | - Shi Wang
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
| | - Zhen-Yu Jia
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
| | - Li Zhu
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
| | - Qi-Yuan Li
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
| | - Wei-Min Zhao
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
| | - Cheng-Long Xue
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
| | - Yong-Jie Xu
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
| | - Zhen Ma
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
| | - Jinsheng Wen
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Shun-Li Yu
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Jian-Xin Li
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Shao-Chun Li
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
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43
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Wang X, Song Z, Wen W, Liu H, Wu J, Dang C, Hossain M, Iqbal MA, Xie L. Potential 2D Materials with Phase Transitions: Structure, Synthesis, and Device Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1804682. [PMID: 30393917 DOI: 10.1002/adma.201804682] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 09/04/2018] [Indexed: 06/08/2023]
Abstract
Layered materials with phase transitions, such as charge density wave (CDW) and magnetic and dipole ordering, have potential to be exfoliated into monolayers and few-layers and then become a large and important subfamily of two-dimensional (2D) materials. Benefitting from enriched physical properties from the collective interactions, long-range ordering, and related phase transitions, as well as the atomic thickness yet having nondangling bonds on the surface, 2D phase-transition materials have vast potential for use in new-concept and functional devices. Here, potential 2D phase-transition materials with CDWs and magnetic and dipole ordering, including transition metal dichalcogenides, transition metal halides, metal thio/selenophosphates, chromium silicon/germanium tellurides, and more, are introduced. The structures and experimental phase-transition properties are summarized for the bulk materials and some of the obtained monolayers. In addition, recent experimental progress on the synthesis and measurement of monolayers, such as 1T-TaS2 , CrI3 , and Cr2 Ge2 Te6 , is reviewed.
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Affiliation(s)
- Xinsheng Wang
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Zhigang Song
- Department of Engineering, University of Cambridge, JJ Thomson Avenue, CB3 0FA, Cambridge, UK
| | - Wen Wen
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Haining Liu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Juanxia Wu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Chunhe Dang
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Mongur Hossain
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Muhammad Ahsan Iqbal
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Liming Xie
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
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44
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Park JW, Cho GY, Lee J, Yeom HW. Emergent honeycomb network of topological excitations in correlated charge density wave. Nat Commun 2019; 10:4038. [PMID: 31492870 PMCID: PMC6731227 DOI: 10.1038/s41467-019-11981-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Accepted: 08/14/2019] [Indexed: 11/09/2022] Open
Abstract
When two periodic potentials compete in materials, one may adopt the other, which straightforwardly generates topological defects. Of particular interest are domain walls in charge-, dipole-, and spin-ordered systems, which govern macroscopic properties and important functionality. However, detailed atomic and electronic structures of domain walls have often been uncertain and the microscopic mechanism of their functionality has been elusive. Here, we clarify the complete atomic and electronic structures of the domain wall network, a honeycomb network connected by Z3 vortices, in the nearly commensurate Mott charge-density wave (CDW) phase of 1T-TaS2. Scanning tunneling microscopy resolves characteristic charge orders within domain walls and their vortices. Density functional theory calculations disclose their unique atomic relaxations and the metallic in-gap states confined tightly therein. A generic theory is constructed, which connects this emergent honeycomb network of conducting electrons to the enhanced superconductivity.
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Affiliation(s)
- Jae Whan Park
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), 77 Cheongam-Ro, Pohang, 790-784, Korea
| | - Gil Young Cho
- Department of Physics, Pohang University of Science and Technology, Pohang, 790-784, Korea
| | - Jinwon Lee
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), 77 Cheongam-Ro, Pohang, 790-784, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang, 790-784, Korea
| | - Han Woong Yeom
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), 77 Cheongam-Ro, Pohang, 790-784, Korea.
- Department of Physics, Pohang University of Science and Technology, Pohang, 790-784, Korea.
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45
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Song SK, Samad A, Wippermann S, Yeom HW. Dynamical Metal to Charge-Density-Wave Junctions in an Atomic Wire Array. NANO LETTERS 2019; 19:5769-5773. [PMID: 31276408 DOI: 10.1021/acs.nanolett.9b02438] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We investigated the atomic scale electronic phase separation emerging from a quasi-1D charge-density-wave (CDW) state of the In atomic wire array on a Si(111) surface. Spatial variations of the CDW gap and amplitude are quantified for various interfaces of metallic and insulating CDW domains by scanning tunneling microscopy and spectroscopy (STS). The strong anisotropy in the metal-insulator junctions is revealed with an order of magnitude difference in the interwire and intrawire junction lengths of 0.4 and 7 nm, respectively. The intrawire junction length is reduced dramatically by an atomic scale impurity, indicating the tunability of the metal-insulator junction in an atomic scale. Density functional theory calculations disclose the dynamical nature of the intrawire junction formation and tunability.
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Affiliation(s)
- Sun Kyu Song
- Center for Artificial Low Dimensional Electronic Systems , Institute for Basic Science (IBS) , Pohang 37673 , Republic of Korea
- Department of Physics , Pohang University of Science and Technology (POSTECH) , Pohang 37673 , Republic of Korea
| | - Abdus Samad
- Max-Planck-Institut für Eisenforschung GmbH , Düsseldorf 40237 , Germany
| | - Stefan Wippermann
- Max-Planck-Institut für Eisenforschung GmbH , Düsseldorf 40237 , Germany
| | - Han Woong Yeom
- Center for Artificial Low Dimensional Electronic Systems , Institute for Basic Science (IBS) , Pohang 37673 , Republic of Korea
- Department of Physics , Pohang University of Science and Technology (POSTECH) , Pohang 37673 , Republic of Korea
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46
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Shao Z, Fu ZG, Li S, Cao Y, Bian Q, Sun H, Zhang Z, Gedeon H, Zhang X, Liu L, Cheng Z, Zheng F, Zhang P, Pan M. Strongly Compressed Few-Layered SnSe 2 Films Grown on a SrTiO 3 Substrate: The Coexistence of Charge Ordering and Enhanced Interfacial Superconductivity. NANO LETTERS 2019; 19:5304-5312. [PMID: 31287705 DOI: 10.1021/acs.nanolett.9b01766] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
High pressure has been demonstrated to be a powerful approach of producing novel condensed-matter states, particularly in tuning the superconducting transition temperature (Tc) of the superconductivity in a clean fashion without involving the complexity of chemical doping. However, the challenge of high-pressure experiment hinders further in-depth research for underlying mechanisms. Here, we have successfully synthesized continuous layer-controllable SnSe2 films on SrTiO3 substrate using molecular beam epitaxy. By means of scanning tunneling microscopy/spectroscopy (STM/S) and Raman spectroscopy, we found that the strong compressive strain is intrinsically built in few-layers films, with a largest equivalent pressure up to 23 GPa in the monolayer. Upon this, unusual 2 × 2 charge ordering is induced at the occupied states in the monolayer, accompanied by prominent decrease in the density of states (DOS) near the Fermi energy (EF), resembling the gap states of CDW reported in transition metal dichalcogenide (TMD) materials. Subsequently, the coexistence of charge ordering and the interfacial superconductivity is observed in bilayer films as a result of releasing the compressive strain. In conjunction with spatially resolved spectroscopic study and first-principles calculation, we find that the enhanced interfacial superconductivity with an estimated Tc of 8.3 K is observed only in the 1 × 1 region. Such superconductivity can be ascribed to a combined effect of interfacial charge transfer and compressive strain, which leads to a considerable downshift of the conduction band minimum and an increase in the DOS at EF. Our results provide an attractive platform for further in-depth investigation of compression-induced charge ordering (monolayer) and the interplay between charge ordering and superconductivity (bilayer). Meanwhile, it has opened up a pathway to prepare strongly compressed two-dimensional materials by growing onto a SrTiO3 substrate, which is promising to induce superconductivity with a higher Tc.
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Affiliation(s)
- Zhibin Shao
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Zhen-Guo Fu
- Institute of Applied Physics and Computational Mathematics , Beijing 100088 , China
| | - Shaojian Li
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Yan Cao
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Qi Bian
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Haigen Sun
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Zongyuan Zhang
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Habakubaho Gedeon
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Xin Zhang
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Lijun Liu
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Zhengwang Cheng
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Fawei Zheng
- Institute of Applied Physics and Computational Mathematics , Beijing 100088 , China
| | - Ping Zhang
- Institute of Applied Physics and Computational Mathematics , Beijing 100088 , China
| | - Minghu Pan
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , China
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Ravnik J, Vaskivskyi I, Gerasimenko Y, Diego M, Vodeb J, Kabanov V, Mihailovic DD. Strain-Induced Metastable Topological Networks in Laser-Fabricated TaS 2 Polytype Heterostructures for Nanoscale Devices. ACS APPLIED NANO MATERIALS 2019; 2:3743-3751. [PMID: 31304463 PMCID: PMC6614884 DOI: 10.1021/acsanm.9b00644] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 05/28/2019] [Indexed: 06/10/2023]
Abstract
The stacking of layered materials into heterostructures offers diverse possibilities for generating deformed moiré states arising from their mutual interaction. Here we report self-assembled two-dimensional nanoscale strain networks formed within a single prismatic (H) polytype monolayer of TaS2 created in situ on the surface of an orthorhombic 1T-TaS2 single crystal by a low-temperature laser-induced polytype transformation. The networks revealed by scanning tunneling microscopy (STM) take on diverse configurations at different temperatures, including extensive double stripes and a twisted 3-gonal mesh of connected 6-pronged vertices. The resulting phase diagram can be understood to be a consequence of thermally driven minimization of discommensurations between the H and 1T layers. Nontrivial dislocation defects of embedded 2- and 4-gonal structures are shown to be associated with local inhomogeneous strains. The creation of metastable heterostructures by laser quench at cryogenic temperatures in combination with STM manipulation of local strain demonstrates nanoscale control of topological defects in transition metal dichalcogenide heterostructures may be utilized in the fabrication of nanoscale electronic devices and neural networks.
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Affiliation(s)
- Jan Ravnik
- Complex
Matter Department, Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - Igor Vaskivskyi
- Center
of Excellence
on Nanoscience and Nanotechnology − Nanocenter (CENN Nanocenter), Jamova 39, SI-1000 Ljubljana, Slovenia
| | - Yaroslav Gerasimenko
- Center
of Excellence
on Nanoscience and Nanotechnology − Nanocenter (CENN Nanocenter), Jamova 39, SI-1000 Ljubljana, Slovenia
| | - Michele Diego
- Complex
Matter Department, Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - Jaka Vodeb
- Complex
Matter Department, Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - Viktor Kabanov
- Complex
Matter Department, Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - Dragan D. Mihailovic
- Complex
Matter Department, Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
- Center
of Excellence
on Nanoscience and Nanotechnology − Nanocenter (CENN Nanocenter), Jamova 39, SI-1000 Ljubljana, Slovenia
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48
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Geremew AK, Rumyantsev S, Kargar F, Debnath B, Nosek A, Bloodgood MA, Bockrath M, Salguero TT, Lake RK, Balandin AA. Bias-Voltage Driven Switching of the Charge-Density-Wave and Normal Metallic Phases in 1T-TaS 2 Thin-Film Devices. ACS NANO 2019; 13:7231-7240. [PMID: 31173685 DOI: 10.1021/acsnano.9b02870] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We report on switching among three charge-density-wave phases, commensurate, nearly commensurate, incommensurate, and the high-temperature normal metallic phase in thin-film 1T-TaS2 devices induced by application of an in-plane bias voltage. The switching among all phases has been achieved over a wide temperature range, from 77 to 400 K. The low-frequency electronic noise spectroscopy has been used as an effective tool for monitoring the transitions, particularly the switching from the incommensurate charge-density-wave phase to the normal metal phase. The noise spectral density exhibits sharp increases at the phase transition points, which correspond to the step-like changes in resistivity. Assignment of the phases is consistent with low-field resistivity measurements over the temperature range from 77 to 600 K. Analysis of the experimental data and calculations of heat dissipation indicate that Joule heating plays a dominant role in the voltage induced transitions in the 1T-TaS2 devices on Si/SiO2 substrates, contrary to some recent claims. The possibility of the bias-voltage switching among four different phases of 1T-TaS2 is a promising step toward nanoscale device applications. The results also demonstrate the potential of noise spectroscopy for investigating and identifying phase transitions in the materials.
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Affiliation(s)
| | - Sergey Rumyantsev
- Center for Terahertz Research and Applications (CENTERA), Institute of High-Pressure Physics , Polish Academy of Sciences , Warsaw 01-142 , Poland
| | | | | | | | - Matthew A Bloodgood
- Department of Chemistry , University of Georgia , Athens , Georgia 30602 , United States
| | | | - Tina T Salguero
- Department of Chemistry , University of Georgia , Athens , Georgia 30602 , United States
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49
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Wang Z, Chu L, Li L, Yang M, Wang J, Eda G, Loh KP. Modulating Charge Density Wave Order in a 1T-TaS 2/Black Phosphorus Heterostructure. NANO LETTERS 2019; 19:2840-2849. [PMID: 30929451 DOI: 10.1021/acs.nanolett.8b04805] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Controllability of collective electron states has been a long-sought scientific and technological goal and promises development of new devices. Herein, we investigate the tuning of charge density wave (CDW) in 1T-TaS2 via a two-dimensional (2D) van der Waals heterostructure of 1T-TaS2/BP. Unusual gate-dependent conductance oscillations were observed in 1T-TaS2 nanoflake supported on BP in transport measurements. Scanning tunneling microscopy study shows that the nearly commensurate (NC) CDW phase survived to 4.5 K in this system, which is substantially lower than the NC to commensurate CDW phase transition temperature of 180 K. A Coulomb blockade model was invoked to explain the conductance oscillations, where the domain walls and domains in NC phase serve as series of quantum dot arrays and tunnelling barriers, respectively. Density functional theory calculations show that a range of interfacial interactions, including strain and charge transfer, influences the CDW stabilities. Our work sheds light on tuning CDW orders via 2D heterostructure stacking and provides new insights on the CDW phase transition and sliding mechanism.
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Affiliation(s)
- Ziying Wang
- Department of Chemistry , National University of Singapore , Singapore 117543
- Centre for Advanced 2D Materials , National University of Singapore, Singapore 117546
| | - Leiqiang Chu
- Department of Chemistry , National University of Singapore , Singapore 117543
- Centre for Advanced 2D Materials , National University of Singapore, Singapore 117546
| | - Linjun Li
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering , Zhejiang University , Hangzhou , China 310027
| | - Ming Yang
- Institute of Materials Research and Engineering, Agency for Science Technology and Research , 2 Fusionopolis Way , Singapore 138634
| | - Junyong Wang
- Centre for Advanced 2D Materials , National University of Singapore, Singapore 117546
- Department of Physics , National University of Singapore, Singapore 117542
| | - Goki Eda
- Department of Chemistry , National University of Singapore , Singapore 117543
- Centre for Advanced 2D Materials , National University of Singapore, Singapore 117546
- Department of Physics , National University of Singapore, Singapore 117542
| | - Kian Ping Loh
- Department of Chemistry , National University of Singapore , Singapore 117543
- Centre for Advanced 2D Materials , National University of Singapore, Singapore 117546
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50
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Karpov P, Brazovskii S. Phase transitions and pattern formation in ensembles of phase-amplitude solitons in quasi-one-dimensional electronic systems. Phys Rev E 2019; 99:022114. [PMID: 30934327 DOI: 10.1103/physreve.99.022114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Indexed: 11/07/2022]
Abstract
Most common types of symmetry breaking in quasi-one-dimensional electronic systems possess a combined manifold of states degenerate with respect to both the phase θ and the amplitude A sign of the order parameter Aexp(iθ). These degrees of freedom can be controlled or accessed independently via either the spin polarization or the charge densities. To understand statistical properties and the phase diagram in the course of cooling under the controlled parameters, we present here an analytical treatment supported by Monte Carlo simulations for a generic coarse-grained two-field model of XY-Ising type. The degeneracies give rise to two coexisting types of topologically nontrivial configurations: phase vortices and amplitude kinks, i.e., the solitons. In two- and three-dimensional states with long-range (or Berezinskii--Kosterlitz--Thouless-type) orders, the topological confinement sets in at a temperature T=T_{1} which binds together the kinks and unusual half-integer vortices. At a lower T=T_{2}, the solitons start to aggregate into walls formed as rods of amplitude kinks which are ultimately terminated by half-integer vortices. With lowering T, the walls multiply, passing sequentially across the sample. The presented results indicate a possible physical realization of a peculiar system of half-integer vortices with rods of amplitude kinks connecting their cores. Its experimental realization becomes feasible in view of recent successes in real-space observations and even manipulations of domain walls in correlated electronic systems.
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Affiliation(s)
- P Karpov
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany.,National University of Science and Technology MISiS, 119991 Moscow, Russia
| | - S Brazovskii
- National University of Science and Technology MISiS, 119991 Moscow, Russia.,LPTMS, CNRS, UMR No. 8626, University of Paris-Sud, University of Paris-Saclay, 91405 Orsay, France.,Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
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