1
|
Neufeld O, Hübener H, Giovannini UD, Rubio A. Tracking electron motion within and outside of Floquet bands from attosecond pulse trains in time-resolved ARPES. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:225401. [PMID: 38364263 DOI: 10.1088/1361-648x/ad2a0e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 02/16/2024] [Indexed: 02/18/2024]
Abstract
Floquet engineering has recently emerged as a technique for controlling material properties with light. Floquet phases can be probed with time- and angle-resolved photoelectron spectroscopy (Tr-ARPES), providing direct access to the laser-dressed electronic bands. Applications of Tr-ARPES to date focused on observing the Floquet-Bloch bands themselves, and their build-up and dephasing on sub-laser-cycle timescales. However, momentum and energy resolved sub-laser-cycle dynamics between Floquet bands have not been analyzed. Given that Floquet theory strictly applies in time-periodic conditions, the notion of resolving sub-laser-cycle dynamics between Floquet states seems contradictory-it requires probe pulse durations below a laser cycle that inherently cannot discern the time-periodic nature of the light-matter system. Here we propose to employ attosecond pulse train probes with the same temporal periodicity as the Floquet-dressing pump pulse, allowing both attosecond sub-laser-cycle resolution and a proper projection of Tr-ARPES spectra on the Floquet-Bloch bands. We formulate and employ this approach inab-initiocalculations in light-driven graphene. Our calculations predict significant sub-laser-cycle dynamics occurring within the Floquet phase with the majority of electrons moving within and in-between Floquet bands, and a small portion residing and moving outside of them in what we denote as 'non-Floquet' bands. We establish that non-Floquet bands arise from the pump laser envelope that induces non-adiabatic electronic excitations during the pulse turn-on and turn-off. By performing calculations in systems with poly-chromatic pumps we also show that Floquet states are not formed on a sub-laser-cycle level. This work indicates that the Floquet-Bloch states are generally not a complete basis set for sub-laser-cycle dynamics in steady-state phases of matter.
Collapse
Affiliation(s)
- Ofer Neufeld
- Max Planck Institute for the Structure and Dynamics of Matter and Center for Free-electron Laser Science, Hamburg 22761, Germany
| | - Hannes Hübener
- Max Planck Institute for the Structure and Dynamics of Matter and Center for Free-electron Laser Science, Hamburg 22761, Germany
| | - Umberto De Giovannini
- Max Planck Institute for the Structure and Dynamics of Matter and Center for Free-electron Laser Science, Hamburg 22761, Germany
- Università degli Studi di Palermo, Dipartimento di Fisica e Chimica-Emilio Segrè, Palermo I-90123, Italy
| | - Angel Rubio
- Max Planck Institute for the Structure and Dynamics of Matter and Center for Free-electron Laser Science, Hamburg 22761, Germany
- Center for Computational Quantum Physics (CCQ), The Flatiron Institute, New York, NY 10010, United States of America
| |
Collapse
|
2
|
Shin D, Rubio A, Tang P. Light-Induced Ideal Weyl Semimetal in HgTe via Nonlinear Phononics. PHYSICAL REVIEW LETTERS 2024; 132:016603. [PMID: 38242673 DOI: 10.1103/physrevlett.132.016603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 11/27/2023] [Accepted: 11/29/2023] [Indexed: 01/21/2024]
Abstract
Interactions between light and matter allow the realization of out-of-equilibrium states in quantum solids. In particular, nonlinear phononics is one of the most efficient approaches to realizing the stationary electronic state in nonequilibrium. Herein, by an extended ab initio molecular dynamics method, we identify that long-lived light-driven quasistationary geometry could stabilize the topological nature in the material family of HgTe compounds. We show that coherent excitation of the infrared-active phonon mode results in a distortion of the atomic geometry with a lifetime of several picoseconds. We show that four Weyl points are located exactly at the Fermi level in this nonequilibrium geometry, making it an ideal long-lived metastable Weyl semimetal. We propose that such a metastable topological phase can be identified by photoelectron spectroscopy of the Fermi arc surface states or ultrafast pump-probe transport measurements of the nonlinear Hall effect.
Collapse
Affiliation(s)
- Dongbin Shin
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
- Max Planck Institute for the Structure and Dynamics of Matter and Center for Free Electron Laser Science, 22761 Hamburg, Germany
| | - Angel Rubio
- Max Planck Institute for the Structure and Dynamics of Matter and Center for Free Electron Laser Science, 22761 Hamburg, Germany
- Nano-Bio Spectroscopy Group, Departamento de Fisica de Materiales, Universidad del País Vasco, UPV/EHU-20018 San Sebastián, Spain
- Center for Computational Quantum Physics (CCQ), The Flatiron Institute, 162 Fifth Avenue, New York, New York 10010, USA
| | - Peizhe Tang
- Max Planck Institute for the Structure and Dynamics of Matter and Center for Free Electron Laser Science, 22761 Hamburg, Germany
- School of Materials Science and Engineering, Beihang University, Beijing 100191, People's Republic of China
| |
Collapse
|
3
|
Zhou S, Bao C, Fan B, Wang F, Zhong H, Zhang H, Tang P, Duan W, Zhou S. Floquet Engineering of Black Phosphorus upon Below-Gap Pumping. PHYSICAL REVIEW LETTERS 2023; 131:116401. [PMID: 37774306 DOI: 10.1103/physrevlett.131.116401] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 07/09/2023] [Accepted: 08/16/2023] [Indexed: 10/01/2023]
Abstract
Time-periodic light field can dress the electronic states and lead to light-induced emergent properties in quantum materials. While below-gap pumping is regarded favorable for Floquet engineering, so far direct experimental evidence of momentum-resolved band renormalization still remains missing. Here, we report experimental evidence of light-induced band renormalization in black phosphorus by pumping at photon energy of 160 meV, which is far below the band gap, and the distinction between below-gap pumping and near-resonance pumping is revealed. Our Letter demonstrates light-induced band engineering upon below-gap pumping, and provides insights for extending Floquet engineering to more quantum materials.
Collapse
Affiliation(s)
- Shaohua Zhou
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
| | - Changhua Bao
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
| | - Benshu Fan
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
| | - Fei Wang
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
| | - Haoyuan Zhong
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
| | - Hongyun Zhang
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
| | - Peizhe Tang
- School of Materials Science and Engineering, Beihang University, Beijing 100191, China
- Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany
| | - Wenhui Duan
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Beijing 100084, China
- Institute for Advanced Study, Tsinghua University, Beijing 100084, China
| | - Shuyun Zhou
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Beijing 100084, China
| |
Collapse
|
4
|
Neufeld O, Hübener H, Jotzu G, De Giovannini U, Rubio A. Band Nonlinearity-Enabled Manipulation of Dirac Nodes, Weyl Cones, and Valleytronics with Intense Linearly Polarized Light. NANO LETTERS 2023; 23:7568-7575. [PMID: 37578460 PMCID: PMC10450813 DOI: 10.1021/acs.nanolett.3c02139] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/29/2023] [Indexed: 08/15/2023]
Abstract
We study low-frequency linearly polarized laser-dressing in materials with valley (graphene and hexagonal-Boron-Nitride) and topological (Dirac- and Weyl-semimetals) properties. In Dirac-like linearly dispersing bands, the laser substantially moves the Dirac nodes away from their original position, and the movement direction can be fully controlled by rotating the laser polarization. We prove that this effect originates from band nonlinearities away from the Dirac nodes. We further demonstrate that this physical mechanism is widely applicable and can move the positions of the valley minima in hexagonal materials to tune valley selectivity, split and move Weyl cones in higher-order Weyl semimetals, and merge Dirac nodes in three-dimensional Dirac semimetals. The model results are validated with ab initio calculations. Our results directly affect efforts for exploring light-dressed electronic structure, suggesting that one can benefit from band nonlinearity for tailoring material properties, and highlight the importance of the full band structure in nonlinear optical phenomena in solids.
Collapse
Affiliation(s)
- Ofer Neufeld
- Center
for Free-electron Laser Science, Max Planck
Institute for the Structure and Dynamics of Matter, Hamburg 22761, Germany
| | - Hannes Hübener
- Center
for Free-electron Laser Science, Max Planck
Institute for the Structure and Dynamics of Matter, Hamburg 22761, Germany
| | - Gregor Jotzu
- Center
for Free-electron Laser Science, Max Planck
Institute for the Structure and Dynamics of Matter, Hamburg 22761, Germany
| | - Umberto De Giovannini
- Center
for Free-electron Laser Science, Max Planck
Institute for the Structure and Dynamics of Matter, Hamburg 22761, Germany
- Dipartimento
di Fisica e Chimica—Emilio Segrè, Università degli Studi di Palermo, Palermo I-90123, Italy
| | - Angel Rubio
- Center
for Free-electron Laser Science, Max Planck
Institute for the Structure and Dynamics of Matter, Hamburg 22761, Germany
- Center
for Computational Quantum Physics (CCQ), The Flatiron Institute, New York, New York 10010, United States
| |
Collapse
|
5
|
Yang C, Esin I, Lewandowski C, Refael G. Optical Control of Slow Topological Electrons in Moiré Systems. PHYSICAL REVIEW LETTERS 2023; 131:026901. [PMID: 37505954 DOI: 10.1103/physrevlett.131.026901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 05/17/2023] [Accepted: 06/13/2023] [Indexed: 07/30/2023]
Abstract
Floquet moiré materials possess optically-induced flat-electron bands with steady-states sensitive to drive parameters. Within this regime, we show that strong interaction screening and phonon bath coupling can overcome enhanced drive-induced heating. In twisted bilayer graphene (TBG) irradiated by a terahertz-frequency continuous circularly polarized laser, the extremely slow electronic states enable the drive to control the steady state occupation of high-Berry curvature electronic states. In particular, above a critical field amplitude, high-Berry-curvature states exhibit a slow regime where they decouple from acoustic phonons, allowing the drive to control the anomalous Hall response. Our work shows that the laser-induced control of topological and transport physics in Floquet TBG are measurable using experimentally available probes.
Collapse
Affiliation(s)
- Christopher Yang
- Department of Physics, IQIM, California Institute of Technology, Pasadena, California 91125, USA
| | - Iliya Esin
- Department of Physics, IQIM, California Institute of Technology, Pasadena, California 91125, USA
| | - Cyprian Lewandowski
- Department of Physics, IQIM, California Institute of Technology, Pasadena, California 91125, USA
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - Gil Refael
- Department of Physics, IQIM, California Institute of Technology, Pasadena, California 91125, USA
| |
Collapse
|
6
|
Ito S, Schüler M, Meierhofer M, Schlauderer S, Freudenstein J, Reimann J, Afanasiev D, Kokh KA, Tereshchenko OE, Güdde J, Sentef MA, Höfer U, Huber R. Build-up and dephasing of Floquet-Bloch bands on subcycle timescales. Nature 2023; 616:696-701. [PMID: 37046087 DOI: 10.1038/s41586-023-05850-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 02/15/2023] [Indexed: 04/14/2023]
Abstract
Strong light fields have created opportunities to tailor novel functionalities of solids1-5. Floquet-Bloch states can form under periodic driving of electrons and enable exotic quantum phases6-15. On subcycle timescales, lightwaves can simultaneously drive intraband currents16-29 and interband transitions18,19,30,31, which enable high-harmonic generation16,18,19,21,22,25,28-30 and pave the way towards ultrafast electronics. Yet, the interplay of intraband and interband excitations and their relation to Floquet physics have been key open questions as dynamical aspects of Floquet states have remained elusive. Here we provide this link by visualizing the ultrafast build-up of Floquet-Bloch bands with time-resolved and angle-resolved photoemission spectroscopy. We drive surface states on a topological insulator32,33 with mid-infrared fields-strong enough for high-harmonic generation-and directly monitor the transient band structure with subcycle time resolution. Starting with strong intraband currents, we observe how Floquet sidebands emerge within a single optical cycle; intraband acceleration simultaneously proceeds in multiple sidebands until high-energy electrons scatter into bulk states and dissipation destroys the Floquet bands. Quantum non-equilibrium calculations explain the simultaneous occurrence of Floquet states with intraband and interband dynamics. Our joint experiment and theory study provides a direct time-domain view of Floquet physics and explores the fundamental frontiers of ultrafast band-structure engineering.
Collapse
Affiliation(s)
- S Ito
- Department of Physics, Philipps-University of Marburg, Marburg, Germany
| | - M Schüler
- Laboratory for Materials Simulations, Paul Scherrer Institute, Villigen PSI, Switzerland
- Department of Physics, University of Fribourg, Fribourg, Switzerland
| | - M Meierhofer
- Department of Physics, University of Regensburg, Regensburg, Germany
| | - S Schlauderer
- Department of Physics, University of Regensburg, Regensburg, Germany
| | - J Freudenstein
- Department of Physics, University of Regensburg, Regensburg, Germany
| | - J Reimann
- Department of Physics, Philipps-University of Marburg, Marburg, Germany
| | - D Afanasiev
- Department of Physics, University of Regensburg, Regensburg, Germany
| | - K A Kokh
- A.V. Rzhanov Institute of Semiconductor Physics and V.S. Sobolev Institute of Geology and Mineralogy SB RAS, Novosibirsk, Russian Federation
| | - O E Tereshchenko
- A.V. Rzhanov Institute of Semiconductor Physics and V.S. Sobolev Institute of Geology and Mineralogy SB RAS, Novosibirsk, Russian Federation
| | - J Güdde
- Department of Physics, Philipps-University of Marburg, Marburg, Germany
| | - M A Sentef
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany.
| | - U Höfer
- Department of Physics, Philipps-University of Marburg, Marburg, Germany.
- Department of Physics, University of Regensburg, Regensburg, Germany.
| | - R Huber
- Department of Physics, University of Regensburg, Regensburg, Germany.
| |
Collapse
|
7
|
Zhan F, Zeng J, Chen Z, Jin X, Fan J, Chen T, Wang R. Floquet Engineering of Nonequilibrium Valley-Polarized Quantum Anomalous Hall Effect with Tunable Chern Number. NANO LETTERS 2023; 23:2166-2172. [PMID: 36883797 DOI: 10.1021/acs.nanolett.2c04651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Here, we propose that Floquet engineering offers a strategy to realize the nonequilibrium quantum anomalous Hall effect (QAHE) with tunable Chern number. Using first-principles calculations and Floquet theorem, we unveil that QAHE related to valley polarization (VP-QAHE) is formed from the hybridization of Floquet sidebands in the two-dimensional family MSi2Z4 (M = Mo, W, V; Z = N, P, As) by irradiating circularly polarized light (CPL). Through the tuning of frequency, intensity, and handedness of CPL, the Chern number of VP-QAHE is highly tunable and up to C = ±4, which attributes to light-induced trigonal warping and multiple-band inversion at different valleys. The chiral edge states and quantized plateau of Hall conductance are visible inside the global band gap, thereby facilitating the experimental measurement. Our work not only establishes Floquet engineering of nonequilibrium VP-QAHE with tunable Chern number in realistic materials but also provides an avenue to explore emergent topological phases under light irradiation.
Collapse
Affiliation(s)
- Fangyang Zhan
- Institute for Structure and Function & Department of Physics & Chongqing Key Laboratory for Strongly Coupled Physics, Chongqing University, Chongqing 400044, P. R. China
| | - Junjie Zeng
- Institute for Structure and Function & Department of Physics & Chongqing Key Laboratory for Strongly Coupled Physics, Chongqing University, Chongqing 400044, P. R. China
| | - Zhuo Chen
- Institute for Structure and Function & Department of Physics & Chongqing Key Laboratory for Strongly Coupled Physics, Chongqing University, Chongqing 400044, P. R. China
| | - Xin Jin
- Institute for Structure and Function & Department of Physics & Chongqing Key Laboratory for Strongly Coupled Physics, Chongqing University, Chongqing 400044, P. R. China
| | - Jing Fan
- Center for Computational Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, P. R. China
| | - Tingyong Chen
- Shenzhen Insitute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, P. R. China
| | - Rui Wang
- Institute for Structure and Function & Department of Physics & Chongqing Key Laboratory for Strongly Coupled Physics, Chongqing University, Chongqing 400044, P. R. China
- Center of Quantum Materials and Devices, Chongqing University, Chongqing 400044, P. R. China
| |
Collapse
|
8
|
Pseudospin-selective Floquet band engineering in black phosphorus. Nature 2023; 614:75-80. [PMID: 36725995 DOI: 10.1038/s41586-022-05610-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 11/30/2022] [Indexed: 02/03/2023]
Abstract
Time-periodic light field has emerged as a control knob for manipulating quantum states in solid-state materials1-3, cold atoms4 and photonic systems5 through hybridization with photon-dressed Floquet states6 in the strong-coupling limit, dubbed Floquet engineering. Such interaction leads to tailored properties of quantum materials7-11, for example, modifications of the topological properties of Dirac materials12,13 and modulation of the optical response14-16. Despite extensive research interests over the past decade3,8,17-20, there is no experimental evidence of momentum-resolved Floquet band engineering of semiconductors, which is a crucial step to extend Floquet engineering to a wide range of solid-state materials. Here, on the basis of time and angle-resolved photoemission spectroscopy measurements, we report experimental signatures of Floquet band engineering in a model semiconductor, black phosphorus. On near-resonance pumping at a photon energy of 340-440 meV, a strong band renormalization is observed near the band edges. In particular, light-induced dynamical gap opening is resolved at the resonance points, which emerges simultaneously with the Floquet sidebands. Moreover, the band renormalization shows a strong selection rule favouring pump polarization along the armchair direction, suggesting pseudospin selectivity for the Floquetband engineering as enforced by the lattice symmetry. Our work demonstrates pseudospin-selective Floquet band engineering in black phosphorus and provides important guiding principles for Floquet engineering of semiconductors.
Collapse
|
9
|
Controlling Floquet states on ultrashort time scales. Nat Commun 2022; 13:7103. [DOI: 10.1038/s41467-022-34973-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 11/14/2022] [Indexed: 11/21/2022] Open
Abstract
AbstractThe advent of ultrafast laser science offers the unique opportunity to combine Floquet engineering with extreme time resolution, further pushing the optical control of matter into the petahertz domain. However, what is the shortest driving pulse for which Floquet states can be realised remains an unsolved matter, thus limiting the application of Floquet theory to pulses composed by many optical cycles. Here we ionized Ne atoms with few-femtosecond pulses of selected time duration and show that a Floquet state can be observed already with a driving field that lasts for only 10 cycles. For shorter pulses, down to 2 cycles, the finite lifetime of the driven state can still be explained using an analytical model based on Floquet theory. By demonstrating that the amplitude and number of Floquet-like sidebands in the photoelectron spectrum can be controlled not only with the driving laser pulse intensity and frequency, but also by its duration, our results add a new lever to the toolbox of Floquet engineering.
Collapse
|
10
|
Tanaka Y, Mochizuki M. Dynamical Phase Transitions in the Photodriven Charge-Ordered Dirac-Electron System. PHYSICAL REVIEW LETTERS 2022; 129:047402. [PMID: 35939024 DOI: 10.1103/physrevlett.129.047402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 05/15/2022] [Accepted: 06/29/2022] [Indexed: 06/15/2023]
Abstract
We study photoinduced phase transitions and charge dynamics in the interacting Dirac-electron system with a charge-ordered ground state theoretically by taking an organic salt α-(BEDT-TTF)_{2}I_{3}. By analyzing the extended Hubbard model for this compound using a combined method of numerical simulations based on the time-dependent Schrödinger equation and the Floquet theory, we observe successive dynamical phase transitions from the charge-ordered insulator to a gapless Dirac semimetal and, eventually, to a Chern insulator phase under irradiation with circularly polarized light. These phase transitions occur as a consequence of two major effects of circularly polarized light, i.e., closing of the charge gap through melting the charge order and opening of the topological gap by breaking the time-reversal symmetry at the Dirac points. We demonstrate that these photoinduced phenomena are governed by charge dynamics of driven correlated Dirac electrons.
Collapse
Affiliation(s)
- Yasuhiro Tanaka
- Department of Applied Physics, Waseda University, Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Masahito Mochizuki
- Department of Applied Physics, Waseda University, Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
| |
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
Karni O, Esin I, Dani KM. Through the Lens of a Momentum Microscope: Viewing Light-Induced Quantum Phenomena in 2D Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022:e2204120. [PMID: 35817468 DOI: 10.1002/adma.202204120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 06/23/2022] [Indexed: 06/15/2023]
Abstract
Van der Waals (vdW) materials at their 2D limit are diverse, flexible, and unique laboratories to study fundamental quantum phenomena and their future applications. Their novel properties rely on their pronounced Coulomb interactions, variety of crystal symmetries and spin-physics, and the ease of incorporation of different vdW materials to form sophisticated heterostructures. In particular, the excited state properties of many 2D semiconductors and semi-metals are relevant for their technological applications, particularly those that can be induced by light. In this paper, the recent advances made in studying out-of-equilibrium, light-induced, phenomena in these materials are reviewed using powerful, surface-sensitive, time-resolved photoemission-based techniques, with a particular emphasis on the emerging multi-dimensional photoemission spectroscopy technique of time-resolved momentum microscopy. The advances this technique has enabled in studying the nature and dynamics of occupied excited states in these materials are discussed. Then, the future research directions opened by these scientific and instrumental advancements are projected for studying the physics of 2D materials and the opportunities to engineer their band-structure and band-topology by laser fields.
Collapse
Affiliation(s)
- Ouri Karni
- Department of Applied Physics, Stanford University, Stanford, CA, 94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Iliya Esin
- Department of Physics, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Keshav M Dani
- Femtosecond Spectroscopy Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, 904-0495, Japan
| |
Collapse
|
13
|
Durden AS, Levine BG. Floquet Time-Dependent Configuration Interaction for Modeling Ultrafast Electron Dynamics. J Chem Theory Comput 2022; 18:795-806. [DOI: 10.1021/acs.jctc.1c01009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Andrew S. Durden
- Department of Chemistry and Institute for Advanced Computational Science, Stony Brook University, Stony Brook, New York 11794, United States
| | - Benjamin G. Levine
- Department of Chemistry and Institute for Advanced Computational Science, Stony Brook University, Stony Brook, New York 11794, United States
| |
Collapse
|