1
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Rajpurohit S, Simoni J, Tan LZ. Photo-induced phase-transitions in complex solids. NANOSCALE ADVANCES 2022; 4:4997-5008. [PMID: 36504738 PMCID: PMC9680828 DOI: 10.1039/d2na00481j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 11/01/2022] [Indexed: 06/17/2023]
Abstract
Photo-induced phase-transitions (PIPTs) driven by highly cooperative interactions are of fundamental interest as they offer a way to tune and control material properties on ultrafast timescales. Due to strong correlations and interactions, complex quantum materials host several fascinating PIPTs such as light-induced charge density waves and ferroelectricity and have become a desirable setting for studying these PIPTs. A central issue in this field is the proper understanding of the underlying mechanisms driving the PIPTs. As these PIPTs are highly nonlinear processes and often involve multiple time and length scales, different theoretical approaches are often needed to understand the underlying mechanisms. In this review, we present a brief overview of PIPTs realized in complex materials, followed by a discussion of the available theoretical methods with selected examples of recent progress in understanding of the nonequilibrium pathways of PIPTs.
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Affiliation(s)
| | - Jacopo Simoni
- Molecular Foundry, Lawrence Berkeley National Laboratory USA
| | - Liang Z Tan
- Molecular Foundry, Lawrence Berkeley National Laboratory USA
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2
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Yamakawa H, Miyamoto T, Morimoto T, Takamura N, Liang S, Yoshimochi H, Terashige T, Kida N, Suda M, Yamamoto HM, Mori H, Miyagawa K, Kanoda K, Okamoto H. Terahertz-field-induced polar charge order in electronic-type dielectrics. Nat Commun 2021; 12:953. [PMID: 33574221 PMCID: PMC7878852 DOI: 10.1038/s41467-021-20925-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 12/29/2020] [Indexed: 11/09/2022] Open
Abstract
Ultrafast electronic-phase change in solids by light, called photoinduced phase transition, is a central issue in the field of non-equilibrium quantum physics, which has been developed very recently. In most of those phenomena, charge or spin orders in an original phase are melted by photocarrier generations, while an ordered state is usually difficult to be created from a non-ordered state by a photoexcitation. Here, we demonstrate that a strong terahertz electric-field pulse changes a Mott insulator of an organic molecular compound in κ-(ET)2Cu[N(CN)2]Cl (ET = bis(ethylenedithio)tetrathiafulvalene), to a macroscopically polarized charge-order state; herein, electronic ferroelectricity is induced by the collective intermolecular charge transfers in each dimer. In contrast, in an isostructural compound, κ-(ET)2Cu2(CN)3, which shows the spin-liquid state at low temperatures, a similar polar charge order is not stabilized by the same terahertz pulse. From the comparative studies of terahertz-field-induced second-harmonic-generation and reflectivity changes in the two compounds, we suggest the possibility that a coupling of charge and spin degrees of freedom would play important roles in the stabilization of polar charge order.
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Affiliation(s)
- H Yamakawa
- Department of Advanced Materials Science, University of Tokyo, Chiba, 277-8561, Japan
| | - T Miyamoto
- Department of Advanced Materials Science, University of Tokyo, Chiba, 277-8561, Japan.
| | - T Morimoto
- Department of Advanced Materials Science, University of Tokyo, Chiba, 277-8561, Japan
| | - N Takamura
- Department of Advanced Materials Science, University of Tokyo, Chiba, 277-8561, Japan
| | - S Liang
- Department of Advanced Materials Science, University of Tokyo, Chiba, 277-8561, Japan
| | - H Yoshimochi
- Department of Applied Physics, University of Tokyo, Bunkyo-Ku, 113-8656, Japan
| | - T Terashige
- AIST-UTokyo Advanced Operand-Measurement Technology Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology, Chiba, 277-8589, Japan
| | - N Kida
- Department of Advanced Materials Science, University of Tokyo, Chiba, 277-8561, Japan
| | - M Suda
- Division of Functional Molecular Systems, Research Center of Integrative Molecular Systems (CIMoS), Institute for Molecular Science, Okazaki, 444-8585, Japan.,Department of Molecular Engineering, Kyoto University, Kyoto, 615-8510, Japan
| | - H M Yamamoto
- Division of Functional Molecular Systems, Research Center of Integrative Molecular Systems (CIMoS), Institute for Molecular Science, Okazaki, 444-8585, Japan
| | - H Mori
- Institute for Solid State Physics, University of Tokyo, Chiba, 277-8581, Japan
| | - K Miyagawa
- Department of Applied Physics, University of Tokyo, Bunkyo-Ku, 113-8656, Japan
| | - K Kanoda
- Department of Applied Physics, University of Tokyo, Bunkyo-Ku, 113-8656, Japan
| | - H Okamoto
- Department of Advanced Materials Science, University of Tokyo, Chiba, 277-8561, Japan. .,AIST-UTokyo Advanced Operand-Measurement Technology Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology, Chiba, 277-8589, Japan.
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3
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Jiang Y, Liu LC, Sarracini A, Krawczyk KM, Wentzell JS, Lu C, Field RL, Matar SF, Gawelda W, Müller-Werkmeister HM, Miller RJD. Direct observation of nuclear reorganization driven by ultrafast spin transitions. Nat Commun 2020; 11:1530. [PMID: 32251278 PMCID: PMC7090058 DOI: 10.1038/s41467-020-15187-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 02/11/2020] [Indexed: 11/24/2022] Open
Abstract
One of the most basic molecular photophysical processes is that of spin transitions and intersystem crossing between excited states surfaces. The change in spin states affects the spatial distribution of electron density through the spin orbit coupling interaction. The subsequent nuclear reorganization reports on the full extent of the spin induced change in electron distribution, which can be treated similarly to intramolecular charge transfer with effective reaction coordinates depicting the spin transition. Here, single-crystal [FeII(bpy)3](PF6)2, a prototypical system for spin crossover (SCO) dynamics, is studied using ultrafast electron diffraction in the single-photon excitation regime. The photoinduced SCO dynamics are resolved, revealing two distinct processes with a (450 ± 20)-fs fast component and a (2.4 ± 0.4)-ps slow component. Using principal component analysis, we uncover the key structural modes, ultrafast Fe–N bond elongations coupled with ligand motions, that define the effective reaction coordinate to fully capture the relevant molecular reorganization. Electron spin is a fundamental property of molecules, and changes in spin state affect both molecular structure and dynamics. Here, the authors resolve, by ultrafast electron diffraction, the nuclear reorganization stabilizing spin transitions in a [FeII(bpy)3](PF6)2 crystal.
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Affiliation(s)
- Yifeng Jiang
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761, Hamburg, Germany.,European XFEL, Holzkoppel 4, 22869, Schenefeld, Germany
| | - Lai Chung Liu
- Departments of Chemistry and Physics, University of Toronto, 80 St. George St., Toronto, M5S 3H6, ON, Canada.,Uncharted Software, 600-2 Berkeley St., Toronto, M5A 4J5, ON, Canada
| | - Antoine Sarracini
- Departments of Chemistry and Physics, University of Toronto, 80 St. George St., Toronto, M5S 3H6, ON, Canada
| | - Kamil M Krawczyk
- Departments of Chemistry and Physics, University of Toronto, 80 St. George St., Toronto, M5S 3H6, ON, Canada
| | - Jordan S Wentzell
- Departments of Chemistry and Physics, University of Toronto, 80 St. George St., Toronto, M5S 3H6, ON, Canada
| | - Cheng Lu
- Departments of Chemistry and Physics, University of Toronto, 80 St. George St., Toronto, M5S 3H6, ON, Canada
| | - Ryan L Field
- Departments of Chemistry and Physics, University of Toronto, 80 St. George St., Toronto, M5S 3H6, ON, Canada
| | - Samir F Matar
- Lebanese German University, LGU, Sahel-Alma, P.O. Box 206, Jounieh, Lebanon
| | - Wojciech Gawelda
- European XFEL, Holzkoppel 4, 22869, Schenefeld, Germany.,Faculty of Physics, Adam Mickiewicz University, ul. Uniwersytetu Poznańskiego 2, 61-614, Poznań, Poland
| | | | - R J Dwayne Miller
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761, Hamburg, Germany. .,Departments of Chemistry and Physics, University of Toronto, 80 St. George St., Toronto, M5S 3H6, ON, Canada.
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4
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Kumagai S, Takaishi S, Iguchi H, Breedlove BK, Kaneko T, Ito H, Kuroda SI, Yamashita M. Correlation between Chemical and Physical Pressures on Charge Bistability in [Pd(en) 2Br](Suc-C n) 2·H 2O. Inorg Chem 2018; 57:12-15. [PMID: 29227105 DOI: 10.1021/acs.inorgchem.7b02566] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hydrostatic (physical) pressure effects on the electrical resistivity of a bromido-bridged palladium compound, [Pd(en)2Br](Suc-C5)2·H2O, were studied. The charge-density-wave to Mott-Hubbard phase transition temperature (TPT) steadily increased with pressure. By a comparison of the effects of the chemical and physical pressures on TPT, it was estimated that the chemical pressure by unit alkyl chain length, i.e., the number of carbon atoms in the alkyl chains within the counterion, corresponded to ca. 1.3 kbar of the physical pressure.
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Affiliation(s)
- Shohei Kumagai
- Department of Chemistry, Graduate School of Science, Tohoku University , 6-3 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Shinya Takaishi
- Department of Chemistry, Graduate School of Science, Tohoku University , 6-3 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Hiroaki Iguchi
- Department of Chemistry, Graduate School of Science, Tohoku University , 6-3 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Brian K Breedlove
- Department of Chemistry, Graduate School of Science, Tohoku University , 6-3 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Takuya Kaneko
- Department of Applied Physics, Graduate School of Engineering, Nagoya University , Chikusa Ward, Furocho, Nagoya 464-0814, Japan
| | - Hiroshi Ito
- Department of Applied Physics, Graduate School of Engineering, Nagoya University , Chikusa Ward, Furocho, Nagoya 464-0814, Japan
| | - Shin-Ichi Kuroda
- Department of Applied Physics, Graduate School of Engineering, Nagoya University , Chikusa Ward, Furocho, Nagoya 464-0814, Japan
| | - Masahiro Yamashita
- Department of Chemistry, Graduate School of Science, Tohoku University , 6-3 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan.,Advanced Institute of Materials Research, Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.,School of Materials Science and Engineering, Nankai University , Tianjin 300350, China
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5
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Yamakawa H, Miyamoto T, Morimoto T, Terashige T, Yada H, Kida N, Suda M, Yamamoto HM, Kato R, Miyagawa K, Kanoda K, Okamoto H. Mott transition by an impulsive dielectric breakdown. NATURE MATERIALS 2017; 16:1100-1105. [PMID: 28825731 DOI: 10.1038/nmat4967] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 07/11/2017] [Indexed: 06/07/2023]
Abstract
The transition of a Mott insulator to metal, the Mott transition, can occur via carrier doping by elemental substitution, and by photoirradiation, as observed in transition-metal compounds and in organic materials. Here, we show that the application of a strong electric field can induce a Mott transition by a new pathway, namely through impulsive dielectric breakdown. Irradiation of a terahertz electric-field pulse on an ET-based compound, κ-(ET) 2Cu[N(CN) 2]Br (ET:bis(ethylenedithio)tetrathiafulvalene), collapses the original Mott gap of ∼30 meV with a ∼0.1 ps time constant after doublon-holon pair productions by quantum tunnelling processes, as indicated by the nonlinear increase of Drude-like low-energy spectral weights. Additionally, we demonstrate metallization using this method is faster than that by a femtosecond laser-pulse irradiation and that the transition dynamics are more electronic and coherent. Thus, strong terahertz-pulse irradiation is an effective approach to achieve a purely electronic Mott transition, enhancing the understanding of its quantum nature.
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Affiliation(s)
- H Yamakawa
- Department of Advanced Materials Science, University of Tokyo, Chiba 277-8561, Japan
| | - T Miyamoto
- Department of Advanced Materials Science, University of Tokyo, Chiba 277-8561, Japan
| | - T Morimoto
- Department of Advanced Materials Science, University of Tokyo, Chiba 277-8561, Japan
| | - T Terashige
- Department of Advanced Materials Science, University of Tokyo, Chiba 277-8561, Japan
| | - H Yada
- Department of Advanced Materials Science, University of Tokyo, Chiba 277-8561, Japan
| | - N Kida
- Department of Advanced Materials Science, University of Tokyo, Chiba 277-8561, Japan
| | - M Suda
- Division of Functional Molecular Systems, Research Center of Integrative Molecular Systems (CIMoS), Institute for Molecular Science, Okazaki 444-8585, Japan
| | - H M Yamamoto
- Division of Functional Molecular Systems, Research Center of Integrative Molecular Systems (CIMoS), Institute for Molecular Science, Okazaki 444-8585, Japan
- RIKEN, Wako 351-0198, Japan
| | - R Kato
- RIKEN, Wako 351-0198, Japan
| | - K Miyagawa
- Department of Applied Physics, University of Tokyo, Bunkyo-ku 113-8656, Japan
| | - K Kanoda
- Department of Applied Physics, University of Tokyo, Bunkyo-ku 113-8656, Japan
| | - H Okamoto
- Department of Advanced Materials Science, University of Tokyo, Chiba 277-8561, Japan
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6
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Current induced polycrystalline-to-crystalline transformation in vanadium dioxide nanowires. Sci Rep 2016; 6:37296. [PMID: 27892519 PMCID: PMC5125010 DOI: 10.1038/srep37296] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 10/27/2016] [Indexed: 11/09/2022] Open
Abstract
Vanadium dioxide (VO2) exhibits a reversible insulator-metal phase transition that is of significant interest in energy-efficient nanoelectronic and nanophotonic devices. In these applications, crystalline materials are usually preferred for their superior electrical transport characteristics as well as spatial homogeneity and low surface roughness over the device area for reduced scattering. Here, we show applied electrical currents can induce a permanent reconfiguration of polycrystalline VO2 nanowires into crystalline nanowires, resulting in a dramatically reduced hysteresis across the phase transition and reduced resistivity. Low currents below 3 mA were sufficient to cause the local temperature in the VO2 to reach about 1780 K to activate the irreversible polycrystalline-to-crystalline transformation. The crystallinity was confirmed by electron microscopy and diffraction analyses. This simple yet localized post-processing of insulator-metal phase transition materials may enable new methods of studying and fabricating nanoscale structures and devices formed from these materials.
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7
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Marino A, Cammarata M, Matar SF, Létard JF, Chastanet G, Chollet M, Glownia JM, Lemke HT, Collet E. Activation of coherent lattice phonon following ultrafast molecular spin-state photo-switching: A molecule-to-lattice energy transfer. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2016; 3:023605. [PMID: 26798836 PMCID: PMC4720109 DOI: 10.1063/1.4936290] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Accepted: 11/09/2015] [Indexed: 05/19/2023]
Abstract
We combine ultrafast optical spectroscopy with femtosecond X-ray absorption to study the photo-switching dynamics of the [Fe(PM-AzA)2(NCS)2] spin-crossover molecular solid. The light-induced excited spin-state trapping process switches the molecules from low spin to high spin (HS) states on the sub-picosecond timescale. The change of the electronic state (<50 fs) induces a structural reorganization of the molecule within 160 fs. This transformation is accompanied by coherent molecular vibrations in the HS potential and especially a rapidly damped Fe-ligand breathing mode. The time-resolved studies evidence a delayed activation of coherent optical phonons of the lattice surrounding the photoexcited molecules.
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Affiliation(s)
- A Marino
- Institute de Physique de Rennes , UMR 6251 University Rennes 1-CNRS, 35042 Rennes, France
| | - M Cammarata
- Institute de Physique de Rennes , UMR 6251 University Rennes 1-CNRS, 35042 Rennes, France
| | - S F Matar
- CNRS, Université de Bordeaux , ICMCB, 87 avenue du Dr. A. Schweitzer, Pessac 33608, France
| | - J-F Létard
- CNRS, Université de Bordeaux , ICMCB, 87 avenue du Dr. A. Schweitzer, Pessac 33608, France
| | - G Chastanet
- CNRS, Université de Bordeaux , ICMCB, 87 avenue du Dr. A. Schweitzer, Pessac 33608, France
| | - M Chollet
- LCLS, SLAC National Laboratory , Menlo Park, California 94025, USA
| | - J M Glownia
- LCLS, SLAC National Laboratory , Menlo Park, California 94025, USA
| | - H T Lemke
- LCLS, SLAC National Laboratory , Menlo Park, California 94025, USA
| | - E Collet
- Institute de Physique de Rennes , UMR 6251 University Rennes 1-CNRS, 35042 Rennes, France
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8
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Ishikawa T, Hayes SA, Keskin S, Corthey G, Hada M, Pichugin K, Marx A, Hirscht J, Shionuma K, Onda K, Okimoto Y, Koshihara SY, Yamamoto T, Cui H, Nomura M, Oshima Y, Abdel-Jawad M, Kato R, Miller RJD. Direct observation of collective modes coupled to molecular orbital-driven charge transfer. Science 2015; 350:1501-5. [DOI: 10.1126/science.aab3480] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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9
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Bertoni R, Lorenc M, Tissot A, Boillot ML, Collet E. Femtosecond photoswitching dynamics and microsecond thermal conversion driven by laser heating in FeIII spin-crossover solids. Coord Chem Rev 2015. [DOI: 10.1016/j.ccr.2014.05.024] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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10
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Onda K, Yamochi H, Koshihara SY. Diverse photoinduced dynamics in an organic charge-transfer complex having strong electron-phonon interactions. Acc Chem Res 2014; 47:3494-503. [PMID: 25340327 DOI: 10.1021/ar500257b] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
CONSPECTUS: Phenomena that occur in nonequilibrium states created by photoexcitation differ qualitatively from those that occur at thermal equilibrium, and various physical theories developed for thermal equilibrium states can hardly be applied to such phenomena. Recently it has been realized that understanding phenomena in nonequilibrium states in solids is important for photoenergy usage and ultrafast computing. Consequently, much effort has been devoted to revealing such phenomena by developing various ultrafast observation techniques and theories applicable to nonequilibrium states. This Account describes our recent studies of diverse photoinduced dynamics in a strongly correlated organic solid using various ultrafast techniques. Solids in which the electronic behavior is affected by Coulomb interactions between electrons are designated as strongly correlated materials and are known to exhibit unique physical properties even at thermal equilibrium. Among them, many organic charge-transfer (CT) complexes have low dimensionality and flexibility in addition to strong correlations; thus, their physical properties change sensitively in response to changes in pressure or electric field. Photoexcitation is also expected to drastically change their physical properties and would be useful for ultrafast photoswitching devices. However, in nonequilibrium states, the complicated dynamics due to these characteristics prevents us from understanding and using these materials for photonic devices. The CT complex (EDO-TTF)2PF6 (EDO-TTF = 4,5-ethylenedioxytetrathiafulvalene) exhibits unique photoinduced dynamics due to strong electron-electron and electron-phonon interactions. We have performed detailed studies of the dynamics of this complex using transient electronic spectroscopy at the 10 and 100 fs time scales. These studies include transient vibrational spectroscopy, which is sensitive to the charges and structures of constituent molecules, and transient electron diffraction, which provides direct information on the crystal structure. Photoexcitation of the charge-ordered low-temperature phase of (EDO-TTF)2PF6 creates a new photoinduced phase over 40 fs via the Franck-Condon state, in which electrons and vibrations are coherently and strongly coupled. This new photoinduced phase is assigned to an insulator-like state in which the charge order differs from that of the initial state. In the photoinduced phase, translations of component molecules proceed before the rearrangements of intramolecular conformations. Subsequently, the charge order and structure gradually approach those of the high-temperature phase over 100 ps. This unusual two-step photoinduced phase transition presumably originates from steric effects due to the bent EDO-TTF as well as strong electron-lattice interactions.
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Affiliation(s)
- Ken Onda
- Interactive
Research Center of Science, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama, Kanagawa 226-8502, Japan
- PRESTO, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Hideki Yamochi
- Research
Center for Low Temperature and Materials Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Shin-ya Koshihara
- Department
of Chemistry and Materials Science, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152-8551, Japan
- CREST, Japan Science and Technology Agency (JST),
O-okayama, Meguro-ku, Tokyo 152-8551, Japan
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11
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Cammarata M, Bertoni R, Lorenc M, Cailleau H, Di Matteo S, Mauriac C, Matar SF, Lemke H, Chollet M, Ravy S, Laulhé C, Létard JF, Collet E. Sequential Activation of Molecular Breathing and Bending during Spin-Crossover Photoswitching Revealed by Femtosecond Optical and X-Ray Absorption Spectroscopy. PHYSICAL REVIEW LETTERS 2014; 113:227402. [PMID: 25494090 DOI: 10.1103/physrevlett.113.227402] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Indexed: 06/04/2023]
Abstract
We study the basic mechanisms allowing light to photoswitch at the molecular scale a spin-crossover material from a low- to a high-spin state. Combined femtosecond x-ray absorption performed at LCLS X-FEL and optical spectroscopy reveal that the structural stabilization of the photoinduced high-spin state results from a two step structural trapping. Molecular breathing vibrations are first activated and rapidly damped as part of the energy is sequentially transferred to molecular bending vibrations. During the photoswitching, the system follows a curved trajectory on the potential energy surface.
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Affiliation(s)
- Marco Cammarata
- Institut de Physique de Rennes, UMR CNRS 6251, Université Rennes 1, 35042 Rennes Cedex, France
| | - Roman Bertoni
- Institut de Physique de Rennes, UMR CNRS 6251, Université Rennes 1, 35042 Rennes Cedex, France
| | - Maciej Lorenc
- Institut de Physique de Rennes, UMR CNRS 6251, Université Rennes 1, 35042 Rennes Cedex, France
| | - Hervé Cailleau
- Institut de Physique de Rennes, UMR CNRS 6251, Université Rennes 1, 35042 Rennes Cedex, France
| | - Sergio Di Matteo
- Institut de Physique de Rennes, UMR CNRS 6251, Université Rennes 1, 35042 Rennes Cedex, France
| | - Cindy Mauriac
- CNRS, Université de Bordeaux, ICMCB, 87 Avenue du Dr. A. Schweitzer, Pessac 33608, France
| | - Samir F Matar
- CNRS, Université de Bordeaux, ICMCB, 87 Avenue du Dr. A. Schweitzer, Pessac 33608, France
| | - Henrik Lemke
- LCLS, SLAC National Laboratory, Menlo Park, California 94025, USA
| | - Matthieu Chollet
- LCLS, SLAC National Laboratory, Menlo Park, California 94025, USA
| | - Sylvain Ravy
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, 91192 Gif-sur-Yvette, France
| | - Claire Laulhé
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, 91192 Gif-sur-Yvette, France
| | - Jean-François Létard
- CNRS, Université de Bordeaux, ICMCB, 87 Avenue du Dr. A. Schweitzer, Pessac 33608, France
| | - Eric Collet
- Institut de Physique de Rennes, UMR CNRS 6251, Université Rennes 1, 35042 Rennes Cedex, France
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12
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Optical freezing of charge motion in an organic conductor. Nat Commun 2014; 5:5528. [DOI: 10.1038/ncomms6528] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 10/09/2014] [Indexed: 11/08/2022] Open
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13
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Matsuzaki H, Iwata M, Miyamoto T, Terashige T, Iwano K, Takaishi S, Takamura M, Kumagai S, Yamashita M, Takahashi R, Wakabayashi Y, Okamoto H. Excitation-photon-energy selectivity of photoconversions in halogen-bridged Pd-chain compounds: Mott insulator to metal or charge-density-wave state. PHYSICAL REVIEW LETTERS 2014; 113:096403. [PMID: 25215998 DOI: 10.1103/physrevlett.113.096403] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Indexed: 06/03/2023]
Abstract
Ultrafast photoinduced transitions of a one-dimensional Mott insulator into two distinct electronic phases, metal and charge-density-wave (CDW) state, were achieved in a bromine-bridged Pd-chain compound [Pd(en)2Br](C5-Y)2H2O (en=ethylenediamine and C5-Y=dialkylsulfosuccinate), by selecting the photon energy of a femtosecond excitation pulse. For the resonant excitation of the Mott-gap transition, excitonic states are generated and converted to one-dimensional CDW domains. For the higher-energy excitation, free electron and hole carriers are produced, giving rise to a transition of the Mott insulator to a metal. Such selectivity in photoconversions by the choice of initial photoexcited states opens a new possibility for the developments of advanced optical switching and memory functions.
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Affiliation(s)
- H Matsuzaki
- Department of Advanced Materials Science, University of Tokyo, Kashiwa, Chiba 277-8561, Japan
| | - M Iwata
- Department of Advanced Materials Science, University of Tokyo, Kashiwa, Chiba 277-8561, Japan
| | - T Miyamoto
- Department of Advanced Materials Science, University of Tokyo, Kashiwa, Chiba 277-8561, Japan
| | - T Terashige
- Department of Advanced Materials Science, University of Tokyo, Kashiwa, Chiba 277-8561, Japan
| | - K Iwano
- Institute of Materials Structure Science, Graduate University for Advanced Studies, High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801, Japan
| | - S Takaishi
- Department of Chemistry, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - M Takamura
- Department of Chemistry, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - S Kumagai
- Department of Chemistry, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - M Yamashita
- Department of Chemistry, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - R Takahashi
- Division of Materials Physics, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan
| | - Y Wakabayashi
- Division of Materials Physics, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan
| | - H Okamoto
- Department of Advanced Materials Science, University of Tokyo, Kashiwa, Chiba 277-8561, Japan
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14
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Takubo N, Tajima N, Yamamoto HM, Kato R. Nonlinear photocurrent with a threshold of excitation density induced by the long-range electron-electron interaction in the charge-ordered molecular conductor (BEDT-TTF)3(ClO4)2. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:055603. [PMID: 24444590 DOI: 10.1088/0953-8984/26/2/055603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We investigated a photoexcited state in the molecular conductor (BEDT-TTF)3(ClO4)2 (BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene) with charge localization due to the electron-electron Coulomb interaction. Photocurrent induced by intramolecular excitation was observed in a charge-ordered insulating state. As a result, nonlinear photocurrent with a threshold of excitation light density was experimentally obtained. The threshold decreased as the temperature increased. This nonlinear photocurrent indicates a transition from an excitonic state to a free excited electronic state. The excitonic state below the threshold is formed by the long-range electron-electron Coulomb interaction. In the free excited electronic state above the threshold, high-density photoexcitation induces Coulomb screening, which results in exciton dissociation and a free electronic state.
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Affiliation(s)
- Naoko Takubo
- RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan
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15
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Tanaka Y, Yonemitsu K. Charge order and possible bias-induced metastable state in the organic conductor β-(meso-DMBEDT-TTF)2PF6: effects of structural distortion. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:465603. [PMID: 24158705 DOI: 10.1088/0953-8984/25/46/465603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We theoretically investigate charge order and nonlinear conduction in the quasi-two-dimensional organic conductor β-(meso-DMBEDT-TTF)2PF6 (DMBEDT-TTF=dimethylbis(ethylenedithio)tetrathiafulvalene). Within the Hartree-Fock approximation, we study the effects of structural distortion on the experimentally observed checkerboard charge order and its bias-induced melting by using an extended Hubbard model with Peierls- and Holstein-types of electron-lattice interactions. The structural distortion is important in realizing the charge order. The current-voltage characteristics obtained by a nonequilibrium Green's function method indicate that a charge-ordered insulating state changes into a conductive state. Although the charge order and lattice distortions are largely suppressed at a threshold voltage, they remain finite even in the conductive state. We discuss the relevance of the results to experimental observations, especially to a possible bias-induced metastable state.
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Affiliation(s)
- Y Tanaka
- Department of Physics, Chuo University, Bunkyo-ku, Tokyo 112-8551, Japan. JST, CREST, Chiyoda-ku, Tokyo 102-0076, Japan
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16
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Itoh K, Itoh H, Naka M, Saito S, Hosako I, Yoneyama N, Ishihara S, Sasaki T, Iwai S. Collective excitation of an electric dipole on a molecular dimer in an organic dimer-Mott insulator. PHYSICAL REVIEW LETTERS 2013; 110:106401. [PMID: 23521274 DOI: 10.1103/physrevlett.110.106401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Revised: 12/21/2012] [Indexed: 06/01/2023]
Abstract
The terahertz response in 10-100 cm(-1) was investigated in an organic dimer-Mott (DM) insulator κ-(ET)(2)Cu(2)(CN)(3) that exhibits a relaxorlike dielectric anomaly. An ~30 cm(-1) band in the optical conductivity was attributable to collective excitation of the fluctuating intradimer electric dipoles that are formed by an electron correlation. We succeeded in observing photoinduced enhancement of this ~30 cm(-1) band, reflecting the growth of the electric dipole cluster in the DM phase. Such optical responses in κ-(ET)(2)Cu(2)(CN)(3) reflect an instability near the boundary between the DM-ferroelectric charge ordered phases.
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Affiliation(s)
- K Itoh
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
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17
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Iwai S, Kawakami Y, Ishikawa T, Sakurai Y, Itoh H, Yamamoto K, Sasaki T. Coherent Electron Dynamics in 10 fs Time Scale in Organic Charge Ordered and Dimer-Mott Insulators. EPJ WEB OF CONFERENCES 2013. [DOI: 10.1051/epjconf/20134103019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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18
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Itoh K, Itoh H, Iwai S, Naka M, Ishihara S, Saito S, Yoneyama N, Sasaki T. Photoinduced Growth of Ferroelectric Charge Order in Organic Dimer-Mott insulator. EPJ WEB OF CONFERENCES 2013. [DOI: 10.1051/epjconf/20134103020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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19
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Photoinduced Phase Transition in Strongly Electron-Lattice and Electron–Electron Correlated Molecular Crystals. CRYSTALS 2012. [DOI: 10.3390/cryst2031067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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20
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Photoinduced Phase Transitions in α-, θ-, and κ-type ET Salts: Ultrafast Melting of the Electronic Ordering. CRYSTALS 2012. [DOI: 10.3390/cryst2020590] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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21
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Sabeth F, Iimori T, Ohta N. Insulator–Metal Transitions Induced by Electric Field and Photoirradiation in Organic Mott Insulator Deuterated κ-(BEDT-TTF)2Cu[N(CN)2]Br. J Am Chem Soc 2012; 134:6984-6. [DOI: 10.1021/ja302725e] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Farzana Sabeth
- Research
Institute for Electronic Science (RIES), Hokkaido University, Sapporo 001-0020, Japan
| | - Toshifumi Iimori
- Research
Institute for Electronic Science (RIES), Hokkaido University, Sapporo 001-0020, Japan
| | - Nobuhiro Ohta
- Research
Institute for Electronic Science (RIES), Hokkaido University, Sapporo 001-0020, Japan
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22
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Theory of Photoinduced Phase Transitions in Molecular Conductors: Interplay Between Correlated Electrons, Lattice Phonons and Molecular Vibrations. CRYSTALS 2012. [DOI: 10.3390/cryst2010056] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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23
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Toda Y, Mertelj T, Naito T, Mihailovic D. Femtosecond carrier relaxation dynamics and photoinduced phase separation in κ-(BEDT-TTF)2Cu[N(CN)2]X (X=Br,Cl). PHYSICAL REVIEW LETTERS 2011; 107:227002. [PMID: 22182038 DOI: 10.1103/physrevlett.107.227002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Indexed: 05/31/2023]
Abstract
We investigate the relaxation dynamics of nonequilibrium carriers in organic conductors κ-(BEDT-TTF)(2)Cu[N(CN)(2)]X (X=Br and Cl) using ultrafast time-resolved optical spectroscopy. The dynamics for both salts show similar temperature dependences, which is well characterized by the carrier relaxation across the pseudogap (PG) of the magnitude Δ(PG) ≈ 16 meV for Br salt and 7.0 meV for Cl salt. On the other hand, only the Br salt shows an abrupt increase of the decay time at low temperature, indicating an additional decay component associated with the superconducting (SC) gap below T(c). The fluence dependent dynamics at low temperature evidences the superposition of the SC component onto the PG component. These results indicate a metallic-insulating phase separation in the Br salt triggered by photoexcited nonequilibrium carriers.
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Affiliation(s)
- Y Toda
- Complex Matter Department, Jozef Stefan Institute, Jamova 39, Ljubljana, SI-1000, Slovenia
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