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Zhang X, Carbin T, Culver AB, Du K, Wang K, Cheong SW, Roy R, Kogar A. Light-induced electronic polarization in antiferromagnetic Cr 2O 3. NATURE MATERIALS 2024; 23:790-795. [PMID: 38561519 DOI: 10.1038/s41563-024-01852-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 03/06/2024] [Indexed: 04/04/2024]
Abstract
In a solid, the electronic subsystem can exhibit incipient order with lower point group symmetry than the crystal lattice. Ultrafast external fields that couple exclusively to electronic order parameters have rarely been investigated, however, despite their potential importance in inducing exotic effects. Here we show that when inversion symmetry is broken by the antiferromagnetic order in Cr2O3, transmitting a linearly polarized light pulse through the crystal gives rise to an in-plane rotational symmetry-breaking (from C3 to C1) via optical rectification. Using interferometric time-resolved second harmonic generation, we show that the ultrafast timescale of the symmetry reduction is indicative of a purely electronic response; the underlying spin and crystal structures remain unaffected. The symmetry-broken state exhibits a dipole moment, and its polar axis can be controlled with the incident light. Our results establish a coherent nonlinear optical protocol by which to break electronic symmetries and produce unconventional electronic effects in solids.
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Affiliation(s)
- Xinshu Zhang
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA, USA
| | - Tyler Carbin
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA, USA
| | - Adrian B Culver
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA, USA
- Mani L. Bhaumik Institute for Theoretical Physics, Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA, USA
| | - Kai Du
- Rutgers Center for Emergent Materials, Rutgers University, Piscataway, NJ, USA
| | - Kefeng Wang
- Rutgers Center for Emergent Materials, Rutgers University, Piscataway, NJ, USA
| | - Sang-Wook Cheong
- Rutgers Center for Emergent Materials, Rutgers University, Piscataway, NJ, USA
| | - Rahul Roy
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA, USA
- Mani L. Bhaumik Institute for Theoretical Physics, Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA, USA
| | - Anshul Kogar
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA, USA.
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2
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Wu S, Fei Z, Sun Z, Yi Y, Xia W, Yan D, Guo Y, Shi Y, Yan J, Cobden DH, Liu WT, Xu X, Wu S. Extrinsic Nonlinear Kerr Rotation in Topological Materials under a Magnetic Field. ACS NANO 2023; 17:18905-18913. [PMID: 37767802 DOI: 10.1021/acsnano.3c04153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/29/2023]
Abstract
Topological properties in quantum materials are often governed by symmetry and tuned by crystal structure and external fields, and hence, symmetry-sensitive nonlinear optical measurements in a magnetic field are a valuable probe. Here, we report nonlinear magneto-optical second harmonic generation (SHG) studies of nonmagnetic topological materials including bilayer WTe2, monolayer WSe2, and bulk TaAs. The polarization-resolved patterns of optical SHG under a magnetic field show nonlinear Kerr rotation in these time-reversal symmetric materials. For materials with 3-fold rotational symmetric lattice structure, the SHG polarization pattern rotates just slightly in a magnetic field, whereas in those with mirror or 2-fold rotational symmetry, the SHG polarization pattern rotates greatly and distorts. These different magneto-SHG characters can be understood by considering the superposition of the magnetic field-induced time-noninvariant nonlinear optical tensor and the crystal-structure-based time-invariant counterpart. The situation is further clarified by scrutinizing the Faraday rotation, whose subtle interplay with crystal symmetry accounts for the diverse behavior of the extrinsic nonlinear Kerr rotation in different materials. Our work illustrates the application of magneto-SHG techniques to directly probe nontrivial topological properties, and underlines the importance of minimizing extrinsic nonlinear Kerr rotation in polarization-resolved magneto-optical studies.
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Affiliation(s)
- Shuang Wu
- State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (MOE), and Department of Physics, Fudan University, Shanghai 200433, China
| | - Zaiyao Fei
- Department of Physics, University of Washington, Seattle, Washington 98195, United States
| | - Zeyuan Sun
- State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (MOE), and Department of Physics, Fudan University, Shanghai 200433, China
| | - Yangfan Yi
- State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (MOE), and Department of Physics, Fudan University, Shanghai 200433, China
| | - Wei Xia
- School of Physical Science and Technology, and ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai 201210, China
| | - Dayu Yan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yanfeng Guo
- School of Physical Science and Technology, and ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai 201210, China
| | - Youguo Shi
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jiaqiang Yan
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - David H Cobden
- Department of Physics, University of Washington, Seattle, Washington 98195, United States
| | - Wei-Tao Liu
- State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (MOE), and Department of Physics, Fudan University, Shanghai 200433, China
| | - Xiaodong Xu
- Department of Physics, University of Washington, Seattle, Washington 98195, United States
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Shiwei Wu
- State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (MOE), and Department of Physics, Fudan University, Shanghai 200433, China
- Shanghai Qi Zhi Institute, Shanghai 200232, China
- Institute for Nanoelectronic Devices and Quantum Computing, and Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 200433, China
- Shanghai Research Center for Quantum Sciences, Shanghai 201315, China
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3
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Hirai D, Fukui A, Sagayama H, Hasegawa T, Hiroi Z. Successive phase transitions of the spin-orbit-coupled metal Cd 2Re 2O 7probed by high-resolution synchrotron x-ray diffraction. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 51:035403. [PMID: 36332269 DOI: 10.1088/1361-648x/aca05e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 11/04/2022] [Indexed: 06/16/2023]
Abstract
The 5dpyrochlore oxide superconductor Cd2Re2O7(CRO) has attracted significant interest as a spin-orbit-coupled metal (SOCM) that spontaneously undergoes a phase transition to an odd-parity multipole phase by breaking the spatial inversion symmetry due to the Fermi liquid instability caused by strong spin-orbit coupling. Despite the significance of structural information during the transition, previous experimental results regarding lattice deformation have been elusive. We have conducted ultra-high resolution synchrotron radiation x-ray diffraction experiments on a high-quality CRO single crystal. The temperature-dependent splitting of the 0 0 16 and 0 0 14 reflections, which are allowed and forbidden, respectively, in the high-temperature cubic phase I (space groupFd-3m), has been clearly observed and reveals the following significant facts: inversion symmetry breaking and tetragonal distortion occur simultaneously atTs1= 201.5(1) K; the previously believed first-order transition between phase II (I-4m2) and phase III (I4122) atTs2∼120 K consists of two close second-order transitions atTs2= 115.4(1) K andTs3∼ 100 K; there is a new orthorhombic phase XI (F222) in between. The order parameters (OPs) of these continuous transitions are uniquely represented by a two-dimensional irreducible representationEuof theOhpoint group, and the OPs of phase XI are a linear combination of those of phases II and III. Each phase is believed to correspond to a distinct odd-parity multipole order, and the complex successive transitions observed may be the result of an electronic phase transition that resolves the Fermi liquid instability in the SOCM.
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Affiliation(s)
- Daigorou Hirai
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
- Department of Applied Physics, Nagoya University, Nagoya 464-8603, Japan
| | - Atsuhito Fukui
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Hajime Sagayama
- Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan
| | - Takumi Hasegawa
- Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima 739-8521, Japan
| | - Zenji Hiroi
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
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4
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Dong T, Zhang SJ, Wang NL. Recent Development of Ultrafast Optical Characterizations for Quantum Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022:e2110068. [PMID: 35853841 DOI: 10.1002/adma.202110068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 06/09/2022] [Indexed: 06/15/2023]
Abstract
The advent of intense ultrashort optical pulses spanning a frequency range from terahertz to the visible has opened a new era in the experimental investigation and manipulation of quantum materials. The generation of strong optical field in an ultrashort time scale enables the steering of quantum materials nonadiabatically, inducing novel phenomenon or creating new phases which may not have an equilibrium counterpart. Ultrafast time-resolved optical techniques have provided rich information and played an important role in characterization of the nonequilibrium and nonlinear properties of solid systems. Here, some of the recent progress of ultrafast optical techniques and their applications to the detection and manipulation of physical properties in selected quantum materials are reviewed. Specifically, the new development in the detection of the Higgs mode and photoinduced nonequilibrium response in the study of superconductors by time-resolved terahertz spectroscopy are discussed.
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Affiliation(s)
- Tao Dong
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Si-Jie Zhang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Nan-Lin Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing, 100871, China
- Beijing Academy of Quantum Information Sciences, Beijing, 100913, China
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5
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Zhang S, Lu X, Liu J. Correlated Insulators, Density Wave States, and Their Nonlinear Optical Response in Magic-Angle Twisted Bilayer Graphene. PHYSICAL REVIEW LETTERS 2022; 128:247402. [PMID: 35776443 DOI: 10.1103/physrevlett.128.247402] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 03/26/2022] [Accepted: 05/24/2022] [Indexed: 06/15/2023]
Abstract
The correlated insulator (CI) states and the recently discovered density wave (DW) states in magic-angle twisted bilayer graphene (TBG) have stimulated intense research interest. However, to date, the nature of these "featureless" correlated states with zero Chern numbers are still elusive and lack a characteristic experimental signature. Thus, an experimental probe to identify the characters of these featureless CI and DW states is urgently needed. In this Letter, we theoretically study the correlated insulators and density wave states at different integer and fractional fillings of the flat bands in magic-angle TBG based on extended unrestricted Hartree-Fock calculations including the Coulomb screening effects from the remote bands. We further investigate the nonlinear optical response of the various correlated states and find that the nonlinear optical conductivities can be used to identify the nature of these CI and DW states at most of the fillings. Therefore, we propose that a nonlinear optical response can serve as a promising experimental probe for unveiling the nature of the CI and DW states observed in magic-angle TBG.
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Affiliation(s)
- Shihao Zhang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Xin Lu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Laboratoire de Physique des Solides, Université Paris-Sud, Université Paris Saclay, CNRS, UMR 8502, F-91405 Orsay Cedex, France
| | - Jianpeng Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai 201210, China
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6
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Harnessing interpretable and unsupervised machine learning to address big data from modern X-ray diffraction. Proc Natl Acad Sci U S A 2022; 119:e2109665119. [PMID: 35679347 PMCID: PMC9214512 DOI: 10.1073/pnas.2109665119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The information content of crystalline materials becomes astronomical when collective electronic behavior and their fluctuations are taken into account. In the past decade, improvements in source brightness and detector technology at modern X-ray facilities have allowed a dramatically increased fraction of this information to be captured. Now, the primary challenge is to understand and discover scientific principles from big datasets when a comprehensive analysis is beyond human reach. We report the development of an unsupervised machine learning approach, X-ray diffraction (XRD) temperature clustering (X-TEC), that can automatically extract charge density wave order parameters and detect intraunit cell ordering and its fluctuations from a series of high-volume X-ray diffraction measurements taken at multiple temperatures. We benchmark X-TEC with diffraction data on a quasi-skutterudite family of materials, (CaxSr[Formula: see text])3Rh4Sn13, where a quantum critical point is observed as a function of Ca concentration. We apply X-TEC to XRD data on the pyrochlore metal, Cd2Re2O7, to investigate its two much-debated structural phase transitions and uncover the Goldstone mode accompanying them. We demonstrate how unprecedented atomic-scale knowledge can be gained when human researchers connect the X-TEC results to physical principles. Specifically, we extract from the X-TEC-revealed selection rules that the Cd and Re displacements are approximately equal in amplitude but out of phase. This discovery reveals a previously unknown involvement of [Formula: see text] Re, supporting the idea of an electronic origin to the structural order. Our approach can radically transform XRD experiments by allowing in operando data analysis and enabling researchers to refine experiments by discovering interesting regions of phase space on the fly.
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7
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Tipping Points and Changes in Australian Climate and Extremes. CLIMATE 2022. [DOI: 10.3390/cli10050073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Systematic changes, since the beginning of the 20th century, in average and extreme Australian rainfall and temperatures indicate that Southern Australian climate has undergone regime transitions into a drier and warmer state. South-west Western Australia (SWWA) experienced the most dramatic drying trend with average streamflow into Perth dams, in the last decade, just 20% of that before the 1960s and extreme, decile 10, rainfall reduced to near zero. In south-eastern Australia (SEA) systematic decreases in average and extreme cool season rainfall became evident in the late 1990s with a halving of the area experiencing average decile 10 rainfall in the early 21st century compared with that for the 20th century. The shift in annual surface temperatures over SWWA and SEA, and indeed for Australia as a whole, has occurred primarily over the last 20 years with the percentage area experiencing extreme maximum temperatures in decile 10 increasing to an average of more than 45% since the start of the 21st century compared with less than 3% for the 20th century mean. Average maximum temperatures have also increased by circa 1 °C for SWWA and SEA over the last 20 years. The climate changes in rainfall an d temperatures are associated with atmospheric circulation shifts.
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8
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Sirica N, Orth PP, Scheurer MS, Dai YM, Lee MC, Padmanabhan P, Mix LT, Teitelbaum SW, Trigo M, Zhao LX, Chen GF, Xu B, Yang R, Shen B, Hu C, Lee CC, Lin H, Cochran TA, Trugman SA, Zhu JX, Hasan MZ, Ni N, Qiu XG, Taylor AJ, Yarotski DA, Prasankumar RP. Photocurrent-driven transient symmetry breaking in the Weyl semimetal TaAs. NATURE MATERIALS 2022; 21:62-66. [PMID: 34750539 DOI: 10.1038/s41563-021-01126-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 09/08/2021] [Indexed: 06/13/2023]
Abstract
Symmetry plays a central role in conventional and topological phases of matter, making the ability to optically drive symmetry changes a critical step in developing future technologies that rely on such control. Topological materials, like topological semimetals, are particularly sensitive to a breaking or restoring of time-reversal and crystalline symmetries, which affect both bulk and surface electronic states. While previous studies have focused on controlling symmetry via coupling to the crystal lattice, we demonstrate here an all-electronic mechanism based on photocurrent generation. Using second harmonic generation spectroscopy as a sensitive probe of symmetry changes, we observe an ultrafast breaking of time-reversal and spatial symmetries following femtosecond optical excitation in the prototypical type-I Weyl semimetal TaAs. Our results show that optically driven photocurrents can be tailored to explicitly break electronic symmetry in a generic fashion, opening up the possibility of driving phase transitions between symmetry-protected states on ultrafast timescales.
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Affiliation(s)
- N Sirica
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA.
| | - P P Orth
- Ames Laboratory, Ames, IA, USA
- Department of Physics and Astronomy, Iowa State University, Ames, IA, USA
| | - M S Scheurer
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck, Austria
| | - Y M Dai
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
- Center for Superconducting Physics and Materials, National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China
| | - M-C Lee
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - P Padmanabhan
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - L T Mix
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - S W Teitelbaum
- Department of Physics, Arizona State Univeristy, Tempe, AZ, USA
- Beus CXFEL Labs, Biodesign Institute, Arizona State Univeristy, Tempe, AZ, USA
| | - M Trigo
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - L X Zhao
- Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - G F Chen
- Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - B Xu
- Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - R Yang
- Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - B Shen
- Department of Physics and Astronomy, University of California, Los Angeles, CA, USA
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, Guangzhou, China
| | - C Hu
- Department of Physics and Astronomy, University of California, Los Angeles, CA, USA
| | - C-C Lee
- Department of Physics, Tamkang University, New Taipei, Taiwan
| | - H Lin
- Institute of Physics, Academia Sinica, Taipei, Taiwan
| | - T A Cochran
- Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, NJ, USA
| | - S A Trugman
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - J-X Zhu
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - M Z Hasan
- Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, NJ, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - N Ni
- Department of Physics and Astronomy, University of California, Los Angeles, CA, USA
| | - X G Qiu
- Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - A J Taylor
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - D A Yarotski
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - R P Prasankumar
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA.
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9
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Uzundal CB, Jamnuch S, Berger E, Woodahl C, Manset P, Hirata Y, Sumi T, Amado A, Akai H, Kubota Y, Owada S, Tono K, Yabashi M, Freeland JW, Schwartz CP, Drisdell WS, Matsuda I, Pascal TA, Zong A, Zuerch M. Polarization-Resolved Extreme-Ultraviolet Second-Harmonic Generation from LiNbO_{3}. PHYSICAL REVIEW LETTERS 2021; 127:237402. [PMID: 34936786 DOI: 10.1103/physrevlett.127.237402] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 08/21/2021] [Accepted: 10/15/2021] [Indexed: 06/14/2023]
Abstract
Second harmonic generation (SHG) spectroscopy ubiquitously enables the investigation of surface chemistry, interfacial chemistry, as well as symmetry properties in solids. Polarization-resolved SHG spectroscopy in the visible to infrared regime is regularly used to investigate electronic and magnetic order through their angular anisotropies within the crystal structure. However, the increasing complexity of novel materials and emerging phenomena hampers the interpretation of experiments solely based on the investigation of hybridized valence states. Here, polarization-resolved SHG in the extreme ultraviolet (XUV-SHG) is demonstrated for the first time, enabling element-resolved angular anisotropy investigations. In noncentrosymmetric LiNbO_{3}, elemental contributions by lithium and niobium are clearly distinguished by energy dependent XUV-SHG measurements. This element-resolved and symmetry-sensitive experiment suggests that the displacement of Li ions in LiNbO_{3}, which is known to lead to ferroelectricity, is accompanied by distortions to the Nb ion environment that breaks the inversion symmetry of the NbO_{6} octahedron as well. Our simulations show that the measured second harmonic spectrum is consistent with Li ion displacements from the centrosymmetric position while the Nb─O bonds are elongated and contracted by displacements of the O atoms. In addition, the polarization-resolved measurement of XUV-SHG shows excellent agreement with numerical predictions based on dipole-induced SHG commonly used in the optical wavelengths. Our result constitutes the first verification of the dipole-based SHG model in the XUV regime. The findings of this work pave the way for future angle and time-resolved XUV-SHG studies with elemental specificity in condensed matter systems.
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Affiliation(s)
- Can B Uzundal
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Sasawat Jamnuch
- ATLAS Materials Science Laboratory, Department of NanoEngineering and Chemical Engineering, University of California, San Diego, La Jolla, California, 92023, USA
| | - Emma Berger
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Clarisse Woodahl
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- University of Florida, Gainesville, Florida 32611, USA
| | - Paul Manset
- Ecole Normale Superieure de Paris, Paris, France
| | - Yasuyuki Hirata
- National Defense Academy of Japan, Yokosuka, Kanagawa 239-8686, Japan
| | - Toshihide Sumi
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Angelique Amado
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Hisazumi Akai
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Yuya Kubota
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan
- Japan Synchrotron Radiation Research Institute, (JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan
| | - Shigeki Owada
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan
- Japan Synchrotron Radiation Research Institute, (JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan
| | - Kensuke Tono
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan
- Japan Synchrotron Radiation Research Institute, (JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan
| | - Makina Yabashi
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan
- Japan Synchrotron Radiation Research Institute, (JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan
| | - John W Freeland
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Craig P Schwartz
- Nevada Extreme Conditions Laboratory, University of Nevada, Las Vegas, Las Vegas, Nevada 89154, USA
| | - Walter S Drisdell
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Iwao Matsuda
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
- Trans-scale Quantum Science Institute, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Tod A Pascal
- ATLAS Materials Science Laboratory, Department of NanoEngineering and Chemical Engineering, University of California, San Diego, La Jolla, California, 92023, USA
- Materials Science and Engineering, University of California San Diego, La Jolla, California, 92023, USA
- Sustainable Power and Energy Center, University of California San Diego, La Jolla, California, 92023, USA
| | - Alfred Zong
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Michael Zuerch
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Fritz Haber Institute of the Max Planck Society, 14195 Berlin, Germany
- Friedrich Schiller University Jena, 07743 Jena, Germany
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10
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Pourovskii LV, Mosca DF, Franchini C. Ferro-octupolar Order and Low-Energy Excitations in d^{2} Double Perovskites of Osmium. PHYSICAL REVIEW LETTERS 2021; 127:237201. [PMID: 34936776 DOI: 10.1103/physrevlett.127.237201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 11/01/2021] [Indexed: 06/14/2023]
Abstract
Conflicting interpretations of experimental data preclude the understanding of the quantum magnetic state of spin-orbit coupled d^{2} double perovskites. Whether the ground state is a Janh-Teller-distorted order of quadrupoles or the hitherto elusive octupolar order remains debated. We resolve this uncertainty through direct calculations of all-rank intersite exchange interactions and inelastic neutron scattering cross section for the d^{2} double perovskite series Ba_{2}MOsO_{6} (M=Ca, Mg, Zn). Using advanced many-body first-principles methods, we show that the ground state is formed by ferro-ordered octupoles coupled by superexchange interactions within the ground-state E_{g} doublet. Computed ordering temperature of the single second-order phase transition is consistent with experimentally observed material-dependent trends. Minuscule distortions of the parent cubic structure are shown to qualitatively modify the structure of gaped magnetic excitations.
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Affiliation(s)
- Leonid V Pourovskii
- Centre de Physique Théorique, Ecole Polytechnique, CNRS, Institut Polytechnique de Paris, 91128 Palaiseau Cedex, France
- Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France
| | - Dario Fiore Mosca
- Faculty of Physics and Center for Computational Materials Science, University of Vienna, Vienna 1090, Austria
| | - Cesare Franchini
- Faculty of Physics and Center for Computational Materials Science, University of Vienna, Vienna 1090, Austria
- Department of Physics and Astronomy "Augusto Righi," Alma Mater Studiorum, Università di Bologna, Bologna 40127, Italy
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11
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Ma Q, Grushin AG, Burch KS. Topology and geometry under the nonlinear electromagnetic spotlight. NATURE MATERIALS 2021; 20:1601-1614. [PMID: 34127824 DOI: 10.1038/s41563-021-00992-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 03/19/2021] [Indexed: 06/12/2023]
Abstract
For many materials, a precise knowledge of their dispersion spectra is insufficient to predict their ordered phases and physical responses. Instead, these materials are classified by the geometrical and topological properties of their wavefunctions. A key challenge is to identify and implement experiments that probe or control these quantum properties. In this Review, we describe recent progress in this direction, focusing on nonlinear electromagnetic responses that arise directly from quantum geometry and topology. We give an overview of the field by discussing theoretical ideas, experiments and the materials that drive them. We conclude by discussing how these techniques can be combined with device architectures to uncover, probe and ultimately control quantum phases with emergent topological and correlated properties.
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Affiliation(s)
- Qiong Ma
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Adolfo G Grushin
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, Grenoble, France
| | - Kenneth S Burch
- Department of Physics, Boston College, Chestnut Hill, MA, USA.
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12
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Qiu WX, Zou JY, Luo AY, Cui ZH, Song ZD, Gao JH, Wang YL, Xu G. Efficient Method for Prediction of Metastable or Ground Multipolar Ordered States and Its Application in Monolayer α-RuX_{3} (X=Cl, I). PHYSICAL REVIEW LETTERS 2021; 127:147202. [PMID: 34652212 DOI: 10.1103/physrevlett.127.147202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 07/26/2021] [Accepted: 08/24/2021] [Indexed: 06/13/2023]
Abstract
Exotic high-rank multipolar order parameters have been found to be unexpectedly active in more and more correlated materials in recent years. Such multipoles are usually dubbed "hidden orders" since they are insensitive to common experimental probes. Theoretically, it is also difficult to predict multipolar orders via ab initio calculations in real materials. Here, we present an efficient method to predict possible multipoles in materials based on linear response theory under random phase approximation. Using this method, we successfully predict two pure metastable magnetic octupolar states in monolayer α-RuCl_{3}, which is confirmed by self-consistent unrestricted Hartree-Fock calculations. We then demonstrate that these octupolar states can be stabilized in monolayer α-RuI_{3}, one of which becomes the octupolar ground state. Furthermore, we also predict a fingerprint of an orthogonal magnetization pattern produced by the octupole moment that can be easily detected by experiment. The method and the example presented in this Letter serve as a guide for searching multipolar order parameters in other correlated materials.
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Affiliation(s)
- Wen-Xuan Qiu
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jin-Yu Zou
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Ai-Yun Luo
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zhi-Hai Cui
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Zhi-Da Song
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Jin-Hua Gao
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yi-Lin Wang
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Gang Xu
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
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13
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Luo X, Obeysekera D, Won C, Sung SH, Schnitzer N, Hovden R, Cheong SW, Yang J, Sun K, Zhao L. Ultrafast Modulations and Detection of a Ferro-Rotational Charge Density Wave Using Time-Resolved Electric Quadrupole Second Harmonic Generation. PHYSICAL REVIEW LETTERS 2021; 127:126401. [PMID: 34597104 DOI: 10.1103/physrevlett.127.126401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 06/04/2021] [Accepted: 08/06/2021] [Indexed: 06/13/2023]
Abstract
We show the ferro-rotational nature of the commensurate charge density wave (CCDW) in 1T-TaS_{2} and track its dynamic modulations by temperature-dependent and time-resolved electric quadrupole rotation anisotropy-second harmonic generation (EQ RA-SHG), respectively. The ultrafast modulations manifest as the breathing and the rotation of the EQ RA-SHG patterns at three frequencies around the reported single CCDW amplitude mode frequency. A sudden shift of the triplet frequencies and a dramatic increase in the breathing and rotation magnitude further reveal a photoinduced transient CDW phase across a critical pump fluence of ∼0.5 mJ/cm^{2}.
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Affiliation(s)
- Xiangpeng Luo
- Department of Physics, University of Michigan, 450 Church St, Ann Arbor, Michigan 48109, USA
| | - Dimuthu Obeysekera
- Department of Physics, New Jersey Institute of Technology, 323 Dr Martin Luther King Jr Blvd, Newark, New Jersey 07102, USA
| | - Choongjae Won
- Laboratory for Pohang Emergent Materials, Pohang Accelerator Laboratory and Max Plank POSTECH Center for Complex Phase Materials, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Suk Hyun Sung
- Department of Materials Sciences, University of Michigan, 2300 Hayward Street, Ann Arbor, Michigan 48109, USA
| | - Noah Schnitzer
- Department of Materials Sciences, University of Michigan, 2300 Hayward Street, Ann Arbor, Michigan 48109, USA
| | - Robert Hovden
- Department of Materials Sciences, University of Michigan, 2300 Hayward Street, Ann Arbor, Michigan 48109, USA
| | - Sang-Wook Cheong
- Laboratory for Pohang Emergent Materials, Pohang Accelerator Laboratory and Max Plank POSTECH Center for Complex Phase Materials, Pohang University of Science and Technology, Pohang 790-784, Korea
- Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Junjie Yang
- Department of Physics, New Jersey Institute of Technology, 323 Dr Martin Luther King Jr Blvd, Newark, New Jersey 07102, USA
| | - Kai Sun
- Department of Physics, University of Michigan, 450 Church St, Ann Arbor, Michigan 48109, USA
| | - Liuyan Zhao
- Department of Physics, University of Michigan, 450 Church St, Ann Arbor, Michigan 48109, USA
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14
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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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15
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Shukla M, Upadhyay R, Tolkiehn M, Upadhyay C. Robust spin-ice freezing in magnetically frustrated Ho 2Ge xTi 2-xO 7pyrochlore. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:465804. [PMID: 32759482 DOI: 10.1088/1361-648x/abace1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Accepted: 08/06/2020] [Indexed: 06/11/2023]
Abstract
Structural analysis of spin frustrated Ho2GexTi2-xO7(x= 0, 0.1, 0.15 & 0.25) pyrochlore oxides has been performed using high resolution x-ray diffraction pattern and low temperature synchrotron x-ray diffraction pattern. The effect of positive chemical pressure on the spin dynamics of Ho2GexTi2-xO7has been analysed through the study of static (M-TandM-H; magnetisation against temperature & magnetisation against magnetic field) and dynamical (ac susceptibility) magnetic measurements. In lower temperature regime (∼2 K), such systems are predominantly governed by competing exchange (Jnn) and dipolar (Dnn) magnetic interactions. Magnetic measurements indicate that the application of increased chemical pressure in Ho2Ti2O7matrix propels the system towards diminished ferromagnetic interaction. Dipolar coupling constant remains almost unchanged but Curie-Weiss temperature (θcw) reduces to -0.04 K from 0.33 K (for an applied magnetic field;H= 100 Oe) with increasingxin Ho2GexTi2-xO7. Positive chemical pressure establishes the dominance of Ho-Ho antiferromagnetic interactionJnnover dipolar interactionDnn. Spin relaxation feature corresponding to thermally activated single ion freezing (Ts∼15 K) is shifted towards lower temperature. This chemical pressure-drivenTsshift is ascribed to the alteration in crystal field effect, which reduces the activation energy for singe ion spin freezing. The reduction in the activation energy indicates crystal field-phonon coupling in Ho2GexTi2-xO7system. The robustness in spin ice freezing (second spin relaxation feature in ac susceptibility curve) remains unaffected with increasingly chemical pressure. This spin freezing ('2 in-2 out' spin arrangement in tetrahedra) is related to quantum tunnelling phenomenon, atTice∼ 2 K. It indicates that majority of spins still follows the 'ice rule' in Ho2GexTi2-xO7even after the application of chemical pressure.
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Affiliation(s)
- Manjari Shukla
- School of Materials Science and Technology, Indian Institute of Technology (Banaras Hindu University) Varanasi -221005, India
| | - Rajnikant Upadhyay
- School of Materials Science and Technology, Indian Institute of Technology (Banaras Hindu University) Varanasi -221005, India
| | - Martin Tolkiehn
- Deutsches Elektronen-Synchrotron (DESY), Notkestraße 85, 22607, Hamburg, Germany
| | - Chandan Upadhyay
- School of Materials Science and Technology, Indian Institute of Technology (Banaras Hindu University) Varanasi -221005, India
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16
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Hornung J, Gottschall T, Opherden L, Antlauf M, Schwarz M, Kroke E, Herrmannsdörfer T, Wosnitza J. Splitting of the magnetic monopole pair-creation energy in spin ice. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:36LT01. [PMID: 32369787 DOI: 10.1088/1361-648x/ab9054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 05/05/2020] [Indexed: 06/11/2023]
Abstract
The thermodynamics in spin-ice systems are governed by emergent magnetic monopole excitations and, until now, the creation of a pair of these topological defects was associated with one specific pair-creation energy. Here, we show that the electric dipole moments inherent to the magnetic monopoles lift the degeneracy of their creation process and lead to a splitting of the pair-creation energy. We consider this finding to extend the model of magnetic relaxation in spin-ice systems and show that an electric dipole interaction in the theoretically estimated order of magnitude leads to a splitting which can explain the controversially discussed discrepancies between the measured temperature dependence of the magnetic relaxation times and previous theory. By applying our extended model to experimental data of, various spin-ice systems, we show its universal applicability and determine a dependence of the electric dipole interaction on the system parameters, which is in accordance with the theoretical model of electric dipole formation.
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Affiliation(s)
- J Hornung
- Dresden High Magnetic Field Laboratory (HLD-EMFL) and Würzburg-Dresden Cluster of Excellence ct.qmat, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
- Institut für Festkörper- und Materialphysik, TU Dresden, 01062 Dresden, Germany
| | - T Gottschall
- Dresden High Magnetic Field Laboratory (HLD-EMFL) and Würzburg-Dresden Cluster of Excellence ct.qmat, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - L Opherden
- Dresden High Magnetic Field Laboratory (HLD-EMFL) and Würzburg-Dresden Cluster of Excellence ct.qmat, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
- Institut für Festkörper- und Materialphysik, TU Dresden, 01062 Dresden, Germany
| | - M Antlauf
- Institut für Anorganische Chemie, TU Bergakademie Freiberg, 09596 Freiberg, Germany
| | - M Schwarz
- Institut für Anorganische Chemie, TU Bergakademie Freiberg, 09596 Freiberg, Germany
| | - E Kroke
- Institut für Anorganische Chemie, TU Bergakademie Freiberg, 09596 Freiberg, Germany
| | - T Herrmannsdörfer
- Dresden High Magnetic Field Laboratory (HLD-EMFL) and Würzburg-Dresden Cluster of Excellence ct.qmat, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - J Wosnitza
- Dresden High Magnetic Field Laboratory (HLD-EMFL) and Würzburg-Dresden Cluster of Excellence ct.qmat, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
- Institut für Festkörper- und Materialphysik, TU Dresden, 01062 Dresden, Germany
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17
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Goswami S, Rath SP, Thompson D, Hedström S, Annamalai M, Pramanick R, Ilic BR, Sarkar S, Hooda S, Nijhuis CA, Martin J, Williams RS, Goswami S, Venkatesan T. Charge disproportionate molecular redox for discrete memristive and memcapacitive switching. NATURE NANOTECHNOLOGY 2020; 15:380-389. [PMID: 32203436 DOI: 10.1038/s41565-020-0653-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 01/31/2020] [Indexed: 05/24/2023]
Abstract
Electronic symmetry breaking by charge disproportionation results in multifaceted changes in the electronic, magnetic and optical properties of a material, triggering ferroelectricity, metal/insulator transition and colossal magnetoresistance. Yet, charge disproportionation lacks technological relevance because it occurs only under specific physical conditions of high or low temperature or high pressure. Here we demonstrate a voltage-triggered charge disproportionation in thin molecular films of a metal-organic complex occurring in ambient conditions. This provides a technologically relevant molecular route for simultaneous realization of a ternary memristor and a binary memcapacitor, scalable down to a device area of 60 nm2. Supported by mathematical modelling, our results establish that multiple memristive states can be functionally non-volatile, yet discrete-a combination perceived as theoretically prohibited. Our device could be used as a binary or ternary memristor, a binary memcapacitor or both concomitantly, and unlike the existing 'continuous state' memristors, its discrete states are optimal for high-density, ultra-low-energy digital computing.
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Affiliation(s)
- Sreetosh Goswami
- NUSNNI-NanoCore, National University of Singapore, Singapore, Singapore.
- NUS Graduate School for Integrative Science and Engineering, National University of Singapore, Singapore, Singapore.
| | - Santi P Rath
- School of Chemical Sciences, Indian Association for the Cultivation of Science (IACS), Kolkata, India
| | - Damien Thompson
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland.
| | - Svante Hedström
- Fysikum, Stockholm University, Stockholm, Sweden
- Svensk Kärnbränslehantering, Solna, Sweden
| | | | - Rajib Pramanick
- School of Chemical Sciences, Indian Association for the Cultivation of Science (IACS), Kolkata, India
| | - B Robert Ilic
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Soumya Sarkar
- NUSNNI-NanoCore, National University of Singapore, Singapore, Singapore
- NUS Graduate School for Integrative Science and Engineering, National University of Singapore, Singapore, Singapore
| | - Sonu Hooda
- NUSNNI-NanoCore, National University of Singapore, Singapore, Singapore
| | - Christian A Nijhuis
- NUSNNI-NanoCore, National University of Singapore, Singapore, Singapore
- Department of Chemistry, National University of Singapore, Singapore, Singapore
- Centre for Advanced 2D Materials, National University of Singapore, Singapore, Singapore
| | - Jens Martin
- NUSNNI-NanoCore, National University of Singapore, Singapore, Singapore.
- Centre for Advanced 2D Materials, National University of Singapore, Singapore, Singapore.
- Department of Physics, National University of Singapore, Singapore, Singapore.
- Leibniz Institut für Kristallzüchtung, Materials Science Department, Berlin, Germany.
| | - R Stanley Williams
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX, USA
| | - Sreebrata Goswami
- School of Chemical Sciences, Indian Association for the Cultivation of Science (IACS), Kolkata, India.
| | - T Venkatesan
- NUSNNI-NanoCore, National University of Singapore, Singapore, Singapore.
- NUS Graduate School for Integrative Science and Engineering, National University of Singapore, Singapore, Singapore.
- Department of Physics, National University of Singapore, Singapore, Singapore.
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore.
- Materials Science and Engineering Department, National University of Singapore, Singapore, Singapore.
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18
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Maharaj DD, Sala G, Stone MB, Kermarrec E, Ritter C, Fauth F, Marjerrison CA, Greedan JE, Paramekanti A, Gaulin BD. Octupolar versus Néel Order in Cubic 5d^{2} Double Perovskites. PHYSICAL REVIEW LETTERS 2020; 124:087206. [PMID: 32167347 DOI: 10.1103/physrevlett.124.087206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 01/30/2020] [Indexed: 05/13/2023]
Abstract
We report time-of-flight neutron spectroscopy and neutron and x-ray diffraction studies of the 5d^{2} double perovskite magnets, Ba_{2}MOsO_{6} (M=Zn,Mg,Ca). These materials host antiferromagnetically coupled 5d^{2} Os^{6+} ions decorating a face-centered cubic (fcc) lattice and are found to remain cubic down to the lowest temperatures. They all exhibit thermodynamic anomalies consistent with a single phase transition at a temperature T^{*}, and a gapped magnetic excitation spectrum with spectral weight concentrated at wave vectors typical of type-I antiferromagnetic orders. However, while muon spin resonance experiments show clear evidence for time-reversal symmetry breaking below T^{*}, we observe no corresponding magnetic Bragg scattering signal. These results are shown to be consistent with ferro-octupolar symmetry breaking below T^{*}, and are discussed in the context of other 5d double perovskite magnets and theories of exotic orders driven by multipolar interactions.
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Affiliation(s)
- D D Maharaj
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - G Sala
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - M B Stone
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - E Kermarrec
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| | - C Ritter
- Institut Laue-Langevin, Boîte Postale 156, 38042 Grenoble Cédex, France
| | - F Fauth
- CELLS-ALBA Synchrotron, Carrer de la Llum 2-26, 08290 Cerdanyola del Vallès, Barcelona, Spain
| | - C A Marjerrison
- Brockhouse Institute for Materials Research, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - J E Greedan
- Brockhouse Institute for Materials Research, McMaster University, Hamilton, Ontario L8S 4M1, Canada
- Department of Chemistry and Chemical Biology, McMaster University, Ontario L8S 4M1, Canada
| | - A Paramekanti
- Department of Physics, University of Toronto, 60 St. George Street, Toronto, Ontario M5S 1A7, Canada
| | - B D Gaulin
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
- Brockhouse Institute for Materials Research, McMaster University, Hamilton, Ontario L8S 4M1, Canada
- Canadian Institute for Advanced Research, 661 University Avenue, Toronto, Ontario M5G 1M1, Canada
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Subramani T, Navrotsky A. Energetics of Formation and Disordering in Rare Earth Weberite RE 3TaO 7 Materials. Inorg Chem 2019; 58:16126-16133. [PMID: 31702141 DOI: 10.1021/acs.inorgchem.9b02675] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The recent finding of local weberite-like ordered domains in disordered and radiation damaged pyrochlore oxides has sparked interest in studying the structure, stability, and order-disorder in compounds that form in the weberite structure. In order to understand the relationships among the energetics, structure, and disordering, weberites of the formula RE3TaO7 (RE = La, Nd, Sm-Yb) were synthesized by conventional solid-state techniques. High temperature oxide melt solution calorimetry was used to determine their enthalpies of formation. Rietveld refinement of PXRD patterns shows that the La compound forms in the weberite La3NbO7 (Cmcm) structure; the Nd compound has both Y3TaO7 (C2221)-type and La3NbO7-type polymorphs; the Sm-Ho compounds crystallize in the weberite Y3TaO7 (C2221) structure; and the Ho-Yb compounds adopt the defect fluorite (Fm3̅m) disordered structure. Depending on the reaction temperature, Ho3TaO7 crystallizes in ordered Y3TaO7 (low temperature) or disordered defect fluorite (high temperature) structures. The formation enthalpy of weberites becomes more exothermic with increasing rare earth ionic radius, implying an increase in stability, i.e., La3TaO7 is most stable and Yb3TaO7 is least stable with respect to the component oxides. The calorimetric data also show that ordered Ho3TaO7 (Y3TaO7 structure) is energetically more stable by 9.2 ± 1.1 kJ/mol than disordered Ho3TaO7 (defect fluorite structure).
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Affiliation(s)
- Tamilarasan Subramani
- Peter A. Rock Thermochemistry Laboratory and NEAT ORU , University of California Davis , Davis , California 95616 , United States
| | - Alexandra Navrotsky
- Peter A. Rock Thermochemistry Laboratory and NEAT ORU , University of California Davis , Davis , California 95616 , United States
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20
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Shinaoka H, Motome Y, Miyake T, Ishibashi S, Werner P. First-principles studies of spin-orbital physics in pyrochlore oxides. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:323001. [PMID: 31140447 DOI: 10.1088/1361-648x/ab162f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The pyrochlore oxides [Formula: see text]O7 exhibit a complex interplay between geometrical frustration, electronic correlations, and spin-orbit coupling (SOC), due to the lattice structure and active charge, spin, and orbital degrees of freedom. Understanding the properties of these materials is a theoretical challenge, because their intricate nature depends on material-specific details and quantum many-body effects. Here we review our recent studies based on first-principles calculations and quantum many-body theories for 4d and 5d pyrochlore oxides with B = Mo, Os, and Ir. In these studies, the SOC and local electron correlations are treated within the local density approximation (LDA) + U and LDA + dynamical mean-field theory formalisms. We also discuss the technical aspects of these calculations.
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Affiliation(s)
- Hiroshi Shinaoka
- Department of Physics, Saitama University, Saitama 338-8570, Japan
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21
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Lu B, Tran JD, Torchinsky DH. Fast reflective optic-based rotational anisotropy nonlinear harmonic generation spectrometer. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:053102. [PMID: 31153244 DOI: 10.1063/1.5080965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 04/04/2019] [Indexed: 06/09/2023]
Abstract
We present a novel Rotational Anisotropy Nonlinear Harmonic Generation (RA-NHG) apparatus based primarily upon reflective optics. The data acquisition scheme used here allow for fast accumulation of RA-NHG traces, mitigating low frequency noise from laser drift, while permitting real-time adjustment of acquired signals with significantly more data points per unit angle rotation of the optics than other RA-NHG setups. We discuss the design and construction of the optical and electronic components of the device and present example data taken on a GaAs test sample at a variety of wavelengths. The RA-second harmonic generation data for this sample show the expected four-fold rotational symmetry across a broad range of wavelengths, while those for RA-third harmonic generation exhibit evidence of cascaded nonlinear processes possible in acentric crystal structures.
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Affiliation(s)
- Baozhu Lu
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - Jason D Tran
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - Darius H Torchinsky
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA
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22
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Hayami S, Yanagi Y, Kusunose H, Motome Y. Electric Toroidal Quadrupoles in the Spin-Orbit-Coupled Metal Cd_{2}Re_{2}O_{7}. PHYSICAL REVIEW LETTERS 2019; 122:147602. [PMID: 31050476 DOI: 10.1103/physrevlett.122.147602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Indexed: 06/09/2023]
Abstract
We report our theoretical results on the order parameters for the pyrochlore metal Cd_{2}Re_{2}O_{7}, which undergoes enigmatic phase transitions with inversion symmetry breaking. By carefully examining active electronic degrees of freedom based on the lattice symmetry, we propose that two parity-breaking phases at ambient pressure are described by unconventional multipoles, electric toroidal quadrupoles (ETQs) with different components, x^{2}-y^{2} and 3z^{2}-r^{2}, in the pyrochlore tetrahedral unit. We elucidate that the ETQs are activated by bond or spin-current order on Re─Re bonds. Our ETQ scenario provides a key to reconciling the experimental contradictions, by measuring ETQ specific phenomena, such as peculiar spin splittings in the electronic band structure, magnetocurrent effect, and nonreciprocal transport under a magnetic field.
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Affiliation(s)
- Satoru Hayami
- Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Yuki Yanagi
- Department of Physics, Meiji University, Kawasaki 214-8571, Japan
| | - Hiroaki Kusunose
- Department of Physics, Meiji University, Kawasaki 214-8571, Japan
| | - Yukitoshi Motome
- Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
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Dimensional crossover in a layered ferromagnet detected by spin correlation driven distortions. Nat Commun 2019; 10:1654. [PMID: 30971694 PMCID: PMC6458139 DOI: 10.1038/s41467-019-09663-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 03/22/2019] [Indexed: 11/18/2022] Open
Abstract
Magneto-elastic distortions are commonly detected across magnetic long-range ordering (LRO) transitions. In principle, they are also induced by the magnetic short-range ordering (SRO) that precedes a LRO transition, which contains information about short-range correlations and energetics that are essential for understanding how LRO is established. However these distortions are difficult to resolve because the associated atomic displacements are exceedingly small and do not break symmetry. Here we demonstrate high-multipole nonlinear optical polarimetry as a sensitive and mode selective probe of SRO induced distortions using CrSiTe3 as a testbed. This compound is composed of weakly bonded sheets of nearly isotropic ferromagnetically interacting spins that, in the Heisenberg limit, would individually be impeded from LRO by the Mermin-Wagner theorem. Our results show that CrSiTe3 evades this law via a two-step crossover from two- to three-dimensional magnetic SRO, manifested through two successive and previously undetected totally symmetric distortions above its Curie temperature. Exploring lattice distortions from magnetic short-range ordering (SRO) facilitates the understanding of magnetic long-range ordering (LRO). Here the authors apply high-multipole nonlinear optical polarimetry to track SRO induced distortions in CrSiTe3, showing that LRO is established via a crossover from two- to three-dimensional SRO.
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24
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Ma Q, Xu SY, Shen H, MacNeill D, Fatemi V, Chang TR, Mier Valdivia AM, Wu S, Du Z, Hsu CH, Fang S, Gibson QD, Watanabe K, Taniguchi T, Cava RJ, Kaxiras E, Lu HZ, Lin H, Fu L, Gedik N, Jarillo-Herrero P. Observation of the nonlinear Hall effect under time-reversal-symmetric conditions. Nature 2018; 565:337-342. [DOI: 10.1038/s41586-018-0807-6] [Citation(s) in RCA: 224] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 11/14/2018] [Indexed: 11/09/2022]
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25
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Lu B, Torchinsky DH. Fourier domain rotational anisotropy-second harmonic generation. OPTICS EXPRESS 2018; 26:33192-33204. [PMID: 30645475 DOI: 10.1364/oe.26.033192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 11/09/2018] [Indexed: 06/09/2023]
Abstract
We describe a novel scheme of detecting rotational anisotropy-second harmonic generation (RA-SHG) signals using a lock-in amplifier referenced to a fast scanning RASHG apparatus. The method directly measures the nth harmonics of the scanning frequency corresponding to SHG signal components of Cn symmetry that appear in a Fourier series expansion of a general RA-SHG signal. GaAs was used as a test sample allowing comparison of point-by-point averaging with the lock-in based method. When divided by the C∞ signal component, the lock-in detected data allowed for both self-referenced determination of ratios of Cn components of up to 1 part in 104 and significantly more sensitive measurement of the relative amount of different Cn components when compared with conventional methods.
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26
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Strongly-coupled quantum critical point in an all-in-all-out antiferromagnet. Nat Commun 2018; 9:2953. [PMID: 30054486 PMCID: PMC6063849 DOI: 10.1038/s41467-018-05435-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 07/02/2018] [Indexed: 12/03/2022] Open
Abstract
Dimensionality and symmetry play deterministic roles in the laws of Nature. They are important tools to characterize and understand quantum phase transitions, especially in the limit of strong correlations between spin, orbit, charge, and structural degrees of freedom. Here, using newly-developed, high-pressure resonant X-ray magnetic and charge diffraction techniques, we have discovered a quantum critical point in Cd2Os2O7 as the all-in-all-out antiferromagnetic order is continuously suppressed to zero temperature and, concomitantly, the cubic lattice structure continuously changes from space group Fd-3m to F-43m. Surrounded by three phases of different time reversal and spatial inversion symmetries, the quantum critical region anchors two phase lines of opposite curvature, with striking departures from a mean-field form at high pressure. As spin fluctuations, lattice breathing modes, and quasiparticle excitations interact in the quantum critical region, we argue that they present the necessary components for strongly-coupled quantum criticality in this three-dimensional compound. The critical behavior of a continuous phase transition is determined by both symmetry and dimensionality. Wang et al. present evidence that the cubic all-in-all-out spin order in Cd2Os2O7 leads to a realization of a non-mean-field strongly-coupled quantum phase transition in three dimensions.
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27
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Frohna K, Deshpande T, Harter J, Peng W, Barker BA, Neaton JB, Louie SG, Bakr OM, Hsieh D, Bernardi M. Inversion symmetry and bulk Rashba effect in methylammonium lead iodide perovskite single crystals. Nat Commun 2018; 9:1829. [PMID: 29739939 PMCID: PMC5940805 DOI: 10.1038/s41467-018-04212-w] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 04/12/2018] [Indexed: 11/08/2022] Open
Abstract
Methylammonium lead iodide perovskite (MAPbI3) exhibits long charge carrier lifetimes that are linked to its high efficiency in solar cells. Yet, the mechanisms governing these unusual carrier dynamics are not completely understood. A leading hypothesis-disproved in this work-is that a large, static bulk Rashba effect slows down carrier recombination. Here, using second harmonic generation rotational anisotropy measurements on MAPbI3 crystals, we demonstrate that the bulk structure of tetragonal MAPbI3 is centrosymmetric with I4/mcm space group. Our calculations show that a significant Rashba splitting in the bandstructure requires a non-centrosymmetric lead iodide framework, and that incorrect structural relaxations are responsible for the previously predicted large Rashba effect. The small Rashba splitting allows us to compute effective masses in excellent agreement with experiment. Our findings rule out the presence of a large static Rashba effect in bulk MAPbI3, and our measurements find no evidence of dynamic Rashba effects.
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Affiliation(s)
- Kyle Frohna
- Department of Applied Physics and Materials Science, California Institute of Technology, Pasadena, CA, 91125, USA
- School of Physics, Trinity College Dublin, Dublin 2, Ireland
| | - Tejas Deshpande
- Department of Physics, California Institute of Technology, Pasadena, CA, 91125, USA
| | - John Harter
- Department of Physics, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Wei Peng
- Division of Physical Sciences and Engineering, KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Bradford A Barker
- Department of Physics, University of California, Berkeley, CA, 94720-7300, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Jeffrey B Neaton
- Department of Physics, University of California, Berkeley, CA, 94720-7300, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Steven G Louie
- Department of Physics, University of California, Berkeley, CA, 94720-7300, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Osman M Bakr
- Division of Physical Sciences and Engineering, KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - David Hsieh
- Department of Physics, California Institute of Technology, Pasadena, CA, 91125, USA.
| | - Marco Bernardi
- Department of Applied Physics and Materials Science, California Institute of Technology, Pasadena, CA, 91125, USA.
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28
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Harter JW, Kennes DM, Chu H, de la Torre A, Zhao ZY, Yan JQ, Mandrus DG, Millis AJ, Hsieh D. Evidence of an Improper Displacive Phase Transition in Cd_{2}Re_{2}O_{7} via Time-Resolved Coherent Phonon Spectroscopy. PHYSICAL REVIEW LETTERS 2018; 120:047601. [PMID: 29437453 DOI: 10.1103/physrevlett.120.047601] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Indexed: 06/08/2023]
Abstract
We have used a combination of ultrafast coherent phonon spectroscopy, ultrafast thermometry, and time-dependent Landau theory to study the inversion symmetry breaking phase transition at T_{c}=200 K in the strongly spin-orbit coupled correlated metal Cd_{2}Re_{2}O_{7}. We establish that the structural distortion at T_{c} is a secondary effect through the absence of any softening of its associated phonon mode, which supports a purely electronically driven mechanism. However, the phonon lifetime exhibits an anomalously strong temperature dependence that decreases linearly to zero near T_{c}. We show that this behavior naturally explains the spurious appearance of phonon softening in previous Raman spectroscopy experiments and should be a prevalent feature of correlated electron systems with linearly coupled order parameters.
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Affiliation(s)
- J W Harter
- Department of Physics, California Institute of Technology, Pasadena, California 91125, USA
- Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
| | - D M Kennes
- Department of Physics, Columbia University, New York, New York 10027, USA
| | - H Chu
- Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
- Department of Applied Physics, California Institute of Technology, Pasadena, California 91125, USA
| | - A de la Torre
- Department of Physics, California Institute of Technology, Pasadena, California 91125, USA
- Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
| | - Z Y Zhao
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - J-Q Yan
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - D G Mandrus
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - A J Millis
- Department of Physics, Columbia University, New York, New York 10027, USA
- Center for Computational Quantum Physics, The Flatiron Institute, New York, New York 10010, USA
| | - D Hsieh
- Department of Physics, California Institute of Technology, Pasadena, California 91125, USA
- Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
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29
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Basov DN, Averitt RD, Hsieh D. Towards properties on demand in quantum materials. NATURE MATERIALS 2017; 16:1077-1088. [PMID: 29066824 DOI: 10.1038/nmat5017] [Citation(s) in RCA: 200] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 09/22/2017] [Indexed: 05/21/2023]
Abstract
The past decade has witnessed an explosion in the field of quantum materials, headlined by the predictions and discoveries of novel Landau-symmetry-broken phases in correlated electron systems, topological phases in systems with strong spin-orbit coupling, and ultra-manipulable materials platforms based on two-dimensional van der Waals crystals. Discovering pathways to experimentally realize quantum phases of matter and exert control over their properties is a central goal of modern condensed-matter physics, which holds promise for a new generation of electronic/photonic devices with currently inaccessible and likely unimaginable functionalities. In this Review, we describe emerging strategies for selectively perturbing microscopic interaction parameters, which can be used to transform materials into a desired quantum state. Particular emphasis will be placed on recent successes to tailor electronic interaction parameters through the application of intense fields, impulsive electromagnetic stimulation, and nanostructuring or interface engineering. Together these approaches outline a potential roadmap to an era of quantum phenomena on demand.
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Affiliation(s)
- D N Basov
- Department of Physics, Columbia University, New York, New York 10027, USA
| | - R D Averitt
- Department of Physics, University of California San Diego, La Jolla, California 92093, USA
| | - D Hsieh
- Department of Physics, California Institute of Technology, Pasadena, California 91125, USA
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30
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Gomilšek M, Klanjšek M, Žitko R, Pregelj M, Bert F, Mendels P, Li Y, Zhang QM, Zorko A. Field-Induced Instability of a Gapless Spin Liquid with a Spinon Fermi Surface. PHYSICAL REVIEW LETTERS 2017; 119:137205. [PMID: 29341713 DOI: 10.1103/physrevlett.119.137205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Indexed: 06/07/2023]
Abstract
The ground state of the quantum kagome antiferromagnet Zn-brochantite, ZnCu_{3}(OH)_{6}SO_{4}, which is one of only a few known spin-liquid (SL) realizations in two or three dimensions, has been described as a gapless SL with a spinon Fermi surface. Employing nuclear magnetic resonance in a broad magnetic-field range down to millikelvin temperatures, we show that in applied magnetic fields this enigmatic state is intrinsically unstable against a SL with a full or a partial gap. A similar instability of the gapless Fermi-surface SL was previously encountered in an organic triangular-lattice antiferromagnet, suggesting a common destabilization mechanism that most likely arises from spinon pairing. A salient property of this instability is that an infinitesimal field suffices to induce it, as predicted theoretically for some other types of gapless SLs.
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Affiliation(s)
- M Gomilšek
- Jožef Stefan Institute, Jamova c. 39, SI-1000 Ljubljana, Slovenia
| | - M Klanjšek
- Jožef Stefan Institute, Jamova c. 39, SI-1000 Ljubljana, Slovenia
| | - R Žitko
- Jožef Stefan Institute, Jamova c. 39, SI-1000 Ljubljana, Slovenia
| | - M Pregelj
- Jožef Stefan Institute, Jamova c. 39, SI-1000 Ljubljana, Slovenia
| | - F Bert
- Laboratoire de Physique des Solides, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay, Cedex, France
| | - P Mendels
- Laboratoire de Physique des Solides, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay, Cedex, France
| | - Y Li
- Department of Physics, Renmin University of China, Beijing 100872, People's Republic of China
| | - Q M Zhang
- Department of Physics, Renmin University of China, Beijing 100872, People's Republic of China
- Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 and Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, People's Republic of China
| | - A Zorko
- Jožef Stefan Institute, Jamova c. 39, SI-1000 Ljubljana, Slovenia
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31
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Affiliation(s)
- J Steven Dodge
- Department of Physics, Simon Fraser University, Burnaby, BC V5A 1S6, Canada. .,Canadian Institute for Advanced Research, Toronto, ON M5G 1Z8, Canada
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