1
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Lee Y, Oang KY, Kim D, Ihee H. A comparative review of time-resolved x-ray and electron scattering to probe structural dynamics. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2024; 11:031301. [PMID: 38706888 PMCID: PMC11065455 DOI: 10.1063/4.0000249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 04/10/2024] [Indexed: 05/07/2024]
Abstract
The structure of molecules, particularly the dynamic changes in structure, plays an essential role in understanding physical and chemical phenomena. Time-resolved (TR) scattering techniques serve as crucial experimental tools for studying structural dynamics, offering direct sensitivity to molecular structures through scattering signals. Over the past decade, the advent of x-ray free-electron lasers (XFELs) and mega-electron-volt ultrafast electron diffraction (MeV-UED) facilities has ushered TR scattering experiments into a new era, garnering significant attention. In this review, we delve into the basic principles of TR scattering experiments, especially focusing on those that employ x-rays and electrons. We highlight the variations in experimental conditions when employing x-rays vs electrons and discuss their complementarity. Additionally, cutting-edge XFELs and MeV-UED facilities for TR x-ray and electron scattering experiments and the experiments performed at those facilities are reviewed. As new facilities are constructed and existing ones undergo upgrades, the landscape for TR x-ray and electron scattering experiments is poised for further expansion. Through this review, we aim to facilitate the effective utilization of these emerging opportunities, assisting researchers in delving deeper into the intricate dynamics of molecular structures.
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Affiliation(s)
| | - Key Young Oang
- Radiation Center for Ultrafast Science, Korea Atomic Energy Research Institute (KAERI), Daejeon 34057, South Korea
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2
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Künzel F, Erpenbeck A, Werner D, Arrigoni E, Gull E, Cohen G, Eckstein M. Numerically Exact Simulation of Photodoped Mott Insulators. PHYSICAL REVIEW LETTERS 2024; 132:176501. [PMID: 38728727 DOI: 10.1103/physrevlett.132.176501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 03/20/2024] [Indexed: 05/12/2024]
Abstract
A description of long-lived photodoped states in Mott insulators is challenging, as it needs to address exponentially separated timescales. We demonstrate how properties of such states can be computed using numerically exact steady state techniques, in particular, the quantum Monte Carlo algorithm, by using a time-local ansatz for the distribution function with separate Fermi functions for the electron and hole quasiparticles. The simulations show that the Mott gap remains robust to large photodoping, and the photodoped state has hole and electron quasiparticles with strongly renormalized properties.
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Affiliation(s)
- Fabian Künzel
- Institute of Theoretical Physics, University of Hamburg, 20355 Hamburg, Germany
| | - André Erpenbeck
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Daniel Werner
- Institute of Theoretical and Computational Physics, Graz University of Technology, 8010 Graz, Austria
| | - Enrico Arrigoni
- Institute of Theoretical and Computational Physics, Graz University of Technology, 8010 Graz, Austria
| | - Emanuel Gull
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Guy Cohen
- The Raymond and Beverley Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
- School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Martin Eckstein
- Institute of Theoretical Physics, University of Hamburg, 20355 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Hamburg, Germany
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3
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Mazzola F, Chaluvadi SK, Polewczyk V, Mondal D, Fujii J, Rajak P, Islam M, Ciancio R, Barba L, Fabrizio M, Rossi G, Orgiani P, Vobornik I. Disentangling Structural and Electronic Properties in V 2O 3 Thin Films: A Genuine Nonsymmetry Breaking Mott Transition. NANO LETTERS 2022; 22:5990-5996. [PMID: 35787096 DOI: 10.1021/acs.nanolett.2c02288] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Phase transitions are key in determining and controlling the quantum properties of correlated materials. Here, by using the combination of material synthesis and photoelectron spectroscopy, we demonstrate a genuine Mott transition undressed of any symmetry breaking side effects in the thin films of V2O3. In particular and in contrast with the bulk V2O3, we unveil the purely electronic dynamics approaching the metal-insulator transition, disentangled from the structural transformation that is prevented by the residual substrate-induced strain. On approaching the transition, the spectral signal evolves slowly over a wide temperature range, the Fermi wave-vector does not change, and the critical temperature is lower than the one reported for the bulk. Our findings are fundamental in demonstrating the universal benchmarks of a genuine nonsymmetry breaking Mott transition, extendable to a large array of correlated quantum systems, and hold promise of exploiting the metal-insulator transition by implementing V2O3 thin films in devices.
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Affiliation(s)
- Federico Mazzola
- CNR-IOM, Area Science Park, Strada Statale 14 km 163.5, I-34149 Trieste, Italy
| | | | - Vincent Polewczyk
- CNR-IOM, Area Science Park, Strada Statale 14 km 163.5, I-34149 Trieste, Italy
| | - Debashis Mondal
- CNR-IOM, Area Science Park, Strada Statale 14 km 163.5, I-34149 Trieste, Italy
| | - Jun Fujii
- CNR-IOM, Area Science Park, Strada Statale 14 km 163.5, I-34149 Trieste, Italy
| | - Piu Rajak
- CNR-IOM, Area Science Park, Strada Statale 14 km 163.5, I-34149 Trieste, Italy
| | - Mahabul Islam
- CNR-IOM, Area Science Park, Strada Statale 14 km 163.5, I-34149 Trieste, Italy
| | - Regina Ciancio
- CNR-IOM, Area Science Park, Strada Statale 14 km 163.5, I-34149 Trieste, Italy
| | - Luisa Barba
- Istituto di Cristallografia del CNR, Strada Statale 14 km 163.5, I-34149 Trieste, Italy
| | - Michele Fabrizio
- International School for Advanced Studies (SISSA), Via Bonomea 265, I-34149 Trieste, Italy
| | - Giorgio Rossi
- CNR-IOM, Area Science Park, Strada Statale 14 km 163.5, I-34149 Trieste, Italy
- University of Milano, Via Celoria 16, I-20133 Milano, Italy
| | - Pasquale Orgiani
- CNR-IOM, Area Science Park, Strada Statale 14 km 163.5, I-34149 Trieste, Italy
| | - Ivana Vobornik
- CNR-IOM, Area Science Park, Strada Statale 14 km 163.5, I-34149 Trieste, Italy
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4
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Nanoscale self-organization and metastable non-thermal metallicity in Mott insulators. Nat Commun 2022; 13:3730. [PMID: 35764628 PMCID: PMC9240065 DOI: 10.1038/s41467-022-31298-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 06/10/2022] [Indexed: 11/08/2022] Open
Abstract
Mott transitions in real materials are first order and almost always associated with lattice distortions, both features promoting the emergence of nanotextured phases. This nanoscale self-organization creates spatially inhomogeneous regions, which can host and protect transient non-thermal electronic and lattice states triggered by light excitation. Here, we combine time-resolved X-ray microscopy with a Landau-Ginzburg functional approach for calculating the strain and electronic real-space configurations. We investigate V2O3, the archetypal Mott insulator in which nanoscale self-organization already exists in the low-temperature monoclinic phase and strongly affects the transition towards the high-temperature corundum metallic phase. Our joint experimental-theoretical approach uncovers a remarkable out-of-equilibrium phenomenon: the photo-induced stabilisation of the long sought monoclinic metal phase, which is absent at equilibrium and in homogeneous materials, but emerges as a metastable state solely when light excitation is combined with the underlying nanotexture of the monoclinic lattice.
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5
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Huitric G, Rodriguez-Fano M, Gournay L, Godin N, Herve M, Privault G, Tranchant J, Khaldi Z, Cammarata M, Collet E, Janod E, ODIN C. Impact of the TeraHertz and Optical pump penetration depths on generated strain waves temporal profiles in a V2O3 thin film. Faraday Discuss 2022; 237:389-405. [DOI: 10.1039/d2fd00013j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Triggering new stable macroscopic orders in materials by ultrafast optical or terahertz pump pulses is a difficult challenge, complicated by the interplay of multiscale microscopic mechanisms, and macroscopic excitation profiles...
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6
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Valmianski I, Rodríguez AF, Rodríguez-Álvarez J, García Del Muro M, Wolowiec C, Kronast F, Ramírez JG, Schuller IK, Labarta A, Batlle X. Driving magnetic domains at the nanoscale by interfacial strain-induced proximity. NANOSCALE 2021; 13:4985-4994. [PMID: 33634814 DOI: 10.1039/d0nr08253h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We investigate the local nanoscale changes of the magnetic anisotropy of a Ni film subject to an inverse magnetostrictive effect by proximity to a V2O3 layer. Using temperature-dependent photoemission electron microscopy (PEEM) combined with X-ray magnetic circular dichroism (XMCD), direct images of the Ni spin alignment across the first-order structural phase transition (SPT) of V2O3 were obtained. We find an abrupt temperature-driven reorientation of the Ni magnetic domains across the SPT, which is associated with a large increase of the coercive field. Moreover, angular dependent ferromagnetic resonance (FMR) shows a remarkable change in the magnetic anisotropy of the Ni film across the SPT of V2O3. Micromagnetic simulations based on these results are in quantitative agreement with the PEEM data. Direct measurements of the lateral correlation length of the Ni domains from XMCD images show an increase of almost one order of magnitude at the SPT compared to room temperature, as well as a broad spatial distribution of the local transition temperatures, thus corroborating the phase coexistence of Ni anisotropies caused by the V2O3 SPT. We show that the rearrangement of the Ni domains is due to strain induced by the oxide layers' structural domains across the SPT. Our results illustrate the use of alternative hybrid systems to manipulate magnetic domains at the nanoscale, which allows for engineering of coercive fields for novel data storage architectures.
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Affiliation(s)
- Ilya Valmianski
- Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla, CA 92093, USA
| | - Arantxa Fraile Rodríguez
- Departament de Física de la Matèria Condensada, Universitat de Barcelona, 08028 Barcelona, Spain and Institut de Nanociència i Nanotecnologia (IN2UB), Universitat de Barcelona, 08028 Barcelona, Spain.
| | - Javier Rodríguez-Álvarez
- Departament de Física de la Matèria Condensada, Universitat de Barcelona, 08028 Barcelona, Spain and Institut de Nanociència i Nanotecnologia (IN2UB), Universitat de Barcelona, 08028 Barcelona, Spain.
| | - Montserrat García Del Muro
- Departament de Física de la Matèria Condensada, Universitat de Barcelona, 08028 Barcelona, Spain and Institut de Nanociència i Nanotecnologia (IN2UB), Universitat de Barcelona, 08028 Barcelona, Spain.
| | - Christian Wolowiec
- Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla, CA 92093, USA
| | - Florian Kronast
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 12489 Berlin, Germany
| | | | - Ivan K Schuller
- Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla, CA 92093, USA
| | - Amílcar Labarta
- Departament de Física de la Matèria Condensada, Universitat de Barcelona, 08028 Barcelona, Spain and Institut de Nanociència i Nanotecnologia (IN2UB), Universitat de Barcelona, 08028 Barcelona, Spain.
| | - Xavier Batlle
- Departament de Física de la Matèria Condensada, Universitat de Barcelona, 08028 Barcelona, Spain and Institut de Nanociència i Nanotecnologia (IN2UB), Universitat de Barcelona, 08028 Barcelona, Spain.
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7
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Golež D, Sun Z, Murakami Y, Georges A, Millis AJ. Nonlinear Spectroscopy of Collective Modes in an Excitonic Insulator. PHYSICAL REVIEW LETTERS 2020; 125:257601. [PMID: 33416346 DOI: 10.1103/physrevlett.125.257601] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 10/26/2020] [Indexed: 06/12/2023]
Abstract
The nonlinear optical response of an excitonic insulator coupled to lattice degrees of freedom is shown to depend in strong and characteristic ways on whether the insulating behavior originates primarily from electron-electron or electron-lattice interactions. Linear response optical signatures of the massive phase mode and the amplitude (Higgs) mode are identified. Upon nonlinear excitation resonant to the phase mode, a new in-gap mode at twice the phase mode frequency is induced, leading to a huge second harmonic response. Excitation of in-gap phonon modes leads to different and much smaller effects. A Landau-Ginzburg theory analysis explains these different behaviors and reveals that a parametric resonance of the strongly excited phase mode is the origin of the photoinduced mode in the electron-dominant case. The difference in the nonlinear optical response serves as a measure of the dominant mechanism of the ordered phase.
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Affiliation(s)
- Denis Golež
- Center for Computational Quantum Physics, Flatiron Institute, 162 Fifth Avenue, New York, New York 10010, USA
- Jožef Stefan Institute, Jamova 39, SI-1000, Ljubljana, Slovenia
| | - Zhiyuan Sun
- Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027, USA
| | - Yuta Murakami
- Department of Physics, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan
| | - Antoine Georges
- Center for Computational Quantum Physics, Flatiron Institute, 162 Fifth Avenue, New York, New York 10010, USA
- Department of Quantum Matter Physics, University of Geneva, 1211 Geneva 4, Switzerland
- CPHT, CNRS, Ecole Polytechnique, IP Paris, F-91128 Palaiseau, France
- Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France
| | - Andrew J Millis
- Center for Computational Quantum Physics, Flatiron Institute, 162 Fifth Avenue, New York, New York 10010, USA
- Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027, USA
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8
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Moreno-Mencía D, Ramos-Álvarez A, Vidas L, Koohpayeh SM, Wall S. Ultrafast evolution and transient phases of a prototype out-of-equilibrium Mott-Hubbard material. Nat Commun 2019; 10:4034. [PMID: 31492852 PMCID: PMC6731218 DOI: 10.1038/s41467-019-11743-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 07/31/2019] [Indexed: 11/09/2022] Open
Affiliation(s)
- David Moreno-Mencía
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860, Castelldefels, Barcelona, Spain
| | - Alberto Ramos-Álvarez
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860, Castelldefels, Barcelona, Spain
| | - Luciana Vidas
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860, Castelldefels, Barcelona, Spain
| | - Seyed M Koohpayeh
- Department of Physics and Astronomy, Institute for Quantum Matter, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Simon Wall
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860, Castelldefels, Barcelona, Spain.
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9
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Reply to: Ultrafast evolution and transient phases of a prototype out-of-equilibrium Mott-Hubbard material. Nat Commun 2019; 10:4035. [PMID: 31492878 PMCID: PMC6731294 DOI: 10.1038/s41467-019-11744-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 07/31/2019] [Indexed: 11/16/2022] Open
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10
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Singer A, Ramirez JG, Valmianski I, Cela D, Hua N, Kukreja R, Wingert J, Kovalchuk O, Glownia JM, Sikorski M, Chollet M, Holt M, Schuller IK, Shpyrko OG. Nonequilibrium Phase Precursors during a Photoexcited Insulator-to-Metal Transition in V_{2}O_{3}. PHYSICAL REVIEW LETTERS 2018; 120:207601. [PMID: 29864371 DOI: 10.1103/physrevlett.120.207601] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Indexed: 06/08/2023]
Abstract
Here, we photoinduce and directly observe with x-ray scattering an ultrafast enhancement of the structural long-range order in the archetypal Mott system V_{2}O_{3}. Despite the ultrafast increase in crystal symmetry, the change of unit cell volume occurs an order of magnitude slower and coincides with the insulator-to-metal transition. The decoupling between the two structural responses in the time domain highlights the existence of a transient photoinduced precursor phase, which is distinct from the two structural phases present in equilibrium. X-ray nanoscopy reveals that acoustic phonons trapped in nanoscale twin domains govern the dynamics of the ultrafast transition into the precursor phase, while nucleation and growth of metallic domains dictate the duration of the slower transition into the metallic phase. The enhancement of the long-range order before completion of the electronic transition demonstrates the critical role the nonequilibrium structural phases play during electronic phase transitions in correlated electrons systems.
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Affiliation(s)
- Andrej Singer
- Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla, California 92093, USA
| | | | - Ilya Valmianski
- Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla, California 92093, USA
| | - Devin Cela
- Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla, California 92093, USA
| | - Nelson Hua
- Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla, California 92093, USA
| | - Roopali Kukreja
- Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla, California 92093, USA
- Center for Memory and Recording Research, University of California San Diego, La Jolla, California 92093, USA
| | - James Wingert
- Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla, California 92093, USA
| | - Olesya Kovalchuk
- Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla, California 92093, USA
| | - James M Glownia
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Marcin Sikorski
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Matthieu Chollet
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Martin Holt
- Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Ivan K Schuller
- Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla, California 92093, USA
| | - Oleg G Shpyrko
- Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla, California 92093, USA
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11
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Peronaci F, Schiró M, Parcollet O. Resonant Thermalization of Periodically Driven Strongly Correlated Electrons. PHYSICAL REVIEW LETTERS 2018; 120:197601. [PMID: 29799256 DOI: 10.1103/physrevlett.120.197601] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Indexed: 06/08/2023]
Abstract
We study the dynamics of the Fermi-Hubbard model driven by a time-periodic modulation of the interaction within nonequilibrium dynamical mean-field theory. For moderate interaction, we find clear evidence of thermalization to a genuine infinite-temperature state with no residual oscillations. Quite differently, in the strongly correlated regime, we find a quasistationary extremely long-lived state with oscillations synchronized with the drive (Floquet prethermalization). Remarkably, the nature of this state dramatically changes upon tuning the drive frequency. In particular, we show the existence of a critical frequency at which the system rapidly thermalizes despite the large interaction. We characterize this resonant thermalization and provide an analytical understanding in terms of a breakdown of the periodic Schrieffer-Wolff transformation.
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Affiliation(s)
- Francesco Peronaci
- Institut de Physique Théorique (IPhT), CEA, CNRS, UMR 3681, 91191 Gif-sur-Yvette, France
| | - Marco Schiró
- Institut de Physique Théorique (IPhT), CEA, CNRS, UMR 3681, 91191 Gif-sur-Yvette, France
| | - Olivier Parcollet
- Institut de Physique Théorique (IPhT), CEA, CNRS, UMR 3681, 91191 Gif-sur-Yvette, France
- Center for Computational Quantum Physics, Flatiron Institute, 162 Fifth Avenue, New York, New York 10010, USA
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12
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Lantz G, Neugebauer MJ, Kubli M, Savoini M, Abreu E, Tasca K, Dornes C, Esposito V, Rittmann J, Windsor YW, Beaud P, Ingold G, Johnson SL. Coupling between a Charge Density Wave and Magnetism in an Heusler Material. PHYSICAL REVIEW LETTERS 2017; 119:227207. [PMID: 29286787 DOI: 10.1103/physrevlett.119.227207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Indexed: 06/07/2023]
Abstract
The prototypical magnetic memory shape alloy Ni_{2}MnGa undergoes various phase transitions as a function of the temperature, pressure, and doping. In the low-temperature phases below 260 K, an incommensurate structural modulation occurs along the [110] direction which is thought to arise from the softening of a phonon mode. It is not at present clear how this phenomenon is related, if at all, to the magnetic memory effect. Here we report time-resolved measurements which track both the structural and magnetic components of the phase transition from the modulated cubic phase as it is brought into the high-symmetry phase. The results suggest that the photoinduced demagnetization modifies the Fermi surface in regions that couple strongly to the periodicity of the structural modulation through the nesting vector. The amplitude of the periodic lattice distortion, however, appears to be less affected by the demagnetization.
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Affiliation(s)
- G Lantz
- Institute for Quantum Electronics, Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
| | - M J Neugebauer
- Institute for Quantum Electronics, Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
| | - M Kubli
- Institute for Quantum Electronics, Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
| | - M Savoini
- Institute for Quantum Electronics, Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
| | - E Abreu
- Institute for Quantum Electronics, Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
| | - K Tasca
- Institute for Quantum Electronics, Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
| | - C Dornes
- Institute for Quantum Electronics, Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
| | - V Esposito
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - J Rittmann
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - Y W Windsor
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - P Beaud
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - G Ingold
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - S L Johnson
- Institute for Quantum Electronics, Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
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13
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Tracking the insulator-to-metal phase transition in VO 2 with few-femtosecond extreme UV transient absorption spectroscopy. Proc Natl Acad Sci U S A 2017; 114:9558-9563. [PMID: 28827356 DOI: 10.1073/pnas.1707602114] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Coulomb correlations can manifest in exotic properties in solids, but how these properties can be accessed and ultimately manipulated in real time is not well understood. The insulator-to-metal phase transition in vanadium dioxide (VO2) is a canonical example of such correlations. Here, few-femtosecond extreme UV transient absorption spectroscopy (FXTAS) at the vanadium M2,3 edge is used to track the insulator-to-metal phase transition in VO2 This technique allows observation of the bulk material in real time, follows the photoexcitation process in both the insulating and metallic phases, probes the subsequent relaxation in the metallic phase, and measures the phase-transition dynamics in the insulating phase. An understanding of the VO2 absorption spectrum in the extreme UV is developed using atomic cluster model calculations, revealing V3+/d2 character of the vanadium center. We find that the insulator-to-metal phase transition occurs on a timescale of 26 ± 6 fs and leaves the system in a long-lived excited state of the metallic phase, driven by a change in orbital occupation. Potential interpretations based on electronic screening effects and lattice dynamics are discussed. A Mott-Hubbard-type mechanism is favored, as the observed timescales and d2 nature of the vanadium metal centers are inconsistent with a Peierls driving force. The findings provide a combined experimental and theoretical roadmap for using time-resolved extreme UV spectroscopy to investigate nonequilibrium dynamics in strongly correlated materials.
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14
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Laulhé C, Huber T, Lantz G, Ferrer A, Mariager SO, Grübel S, Rittmann J, Johnson JA, Esposito V, Lübcke A, Huber L, Kubli M, Savoini M, Jacques VLR, Cario L, Corraze B, Janod E, Ingold G, Beaud P, Johnson SL, Ravy S. Ultrafast Formation of a Charge Density Wave State in 1T-TaS_{2}: Observation at Nanometer Scales Using Time-Resolved X-Ray Diffraction. PHYSICAL REVIEW LETTERS 2017; 118:247401. [PMID: 28665649 DOI: 10.1103/physrevlett.118.247401] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Indexed: 05/19/2023]
Abstract
Femtosecond time-resolved x-ray diffraction is used to study a photoinduced phase transition between two charge density wave (CDW) states in 1T-TaS_{2}, namely the nearly commensurate (NC) and the incommensurate (I) CDW states. Structural modulations associated with the NC-CDW order are found to disappear within 400 fs. The photoinduced I-CDW phase then develops through a nucleation and growth process which ends 100 ps after laser excitation. We demonstrate that the newly formed I-CDW phase is fragmented into several nanometric domains that are growing through a coarsening process. The coarsening dynamics is found to follow the universal Lifshitz-Allen-Cahn growth law, which describes the ordering kinetics in systems exhibiting a nonconservative order parameter.
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Affiliation(s)
- C Laulhé
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin-BP 48, F-91192 Gif-sur-Yvette, France
- Université Paris-Saclay (Université Paris-Sud), F-91405 Orsay Cedex, France
| | - T Huber
- Institute for Quantum Electronics, Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
| | - G Lantz
- Institute for Quantum Electronics, Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
- Laboratoire de Physique des Solides, Université Paris-Sud, CNRS, UMR 8502, F-91405 Orsay, France
| | - A Ferrer
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - S O Mariager
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - S Grübel
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - J Rittmann
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - J A Johnson
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - V Esposito
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - A Lübcke
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - L Huber
- Institute for Quantum Electronics, Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
| | - M Kubli
- Institute for Quantum Electronics, Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
| | - M Savoini
- Institute for Quantum Electronics, Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
| | - V L R Jacques
- Laboratoire de Physique des Solides, Université Paris-Sud, CNRS, UMR 8502, F-91405 Orsay, France
| | - L Cario
- Institut des Matériaux Jean Rouxel-UMR 6502, Université de Nantes, 2 rue de la Houssinière, F-44322 Nantes, France
| | - B Corraze
- Institut des Matériaux Jean Rouxel-UMR 6502, Université de Nantes, 2 rue de la Houssinière, F-44322 Nantes, France
| | - E Janod
- Institut des Matériaux Jean Rouxel-UMR 6502, Université de Nantes, 2 rue de la Houssinière, F-44322 Nantes, France
| | - G Ingold
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - P Beaud
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - S L Johnson
- Institute for Quantum Electronics, Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
| | - S Ravy
- Laboratoire de Physique des Solides, Université Paris-Sud, CNRS, UMR 8502, F-91405 Orsay, France
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