Papers - TAKAYOSHI Shintaro
-
Many-Body Effects on High-Harmonic Generation in Hubbard Ladders Reviewed International coauthorship
Yuta Murakami, Thomas Hansen, Shintaro Takayoshi, Lars Bojer Madsen, Philipp Werner
Physical Review Letters 134 ( 9 ) 096504 2025.3
Publisher：American Physical Society (APS)
DOI： 10.1103/physrevlett.134.096504
Other Link： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevLett.134.096504/fulltext
-
Phase transitions and spin dynamics of the quasi-one dimensional Ising-like antiferromagnet BaCo2V2O8 in a longitudinal magnetic field Reviewed International coauthorship
Shintaro Takayoshi, Quentin Faure, Virginie Simonet, Béatrice Grenier, Sylvain Petit, Jacques Ollivier, Pascal Lejay, Thierry Giamarchi
Physical Review Research 5 ( 2 ) 023205 2023.6
Authorship：Lead author, Corresponding author Publisher：American Physical Society (APS)
DOI： 10.1103/physrevresearch.5.023205
Other Link： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevResearch.5.023205/fulltext
-
Spin, Charge, and η-Spin Separation in One-Dimensional Photodoped Mott Insulators Reviewed International coauthorship
Yuta Murakami, Shintaro Takayoshi, Tatsuya Kaneko, Andreas M. Läuchli, Philipp Werner
Physical Review Letters 130 ( 10 ) 106501 2023.3
Publisher：American Physical Society (APS)
DOI： 10.1103/PhysRevLett.130.106501
Other Link： https://link.aps.org/article/10.1103/PhysRevLett.130.106501
-
Mott memristors based on field-induced carrier avalanche multiplication Reviewed International coauthorship
Francesco Peronaci, Sara Ameli, Shintaro Takayoshi, Alexandra S. Landsman, Takashi Oka
Physical Review B 107 ( 7 ) 075154 2023.2
Publisher：American Physical Society (APS)
DOI： 10.1103/PhysRevB.107.075154
Other Link： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevB.107.075154/fulltext
-
Dynamical conductivity of disordered quantum chains Reviewed International coauthorship
Shintaro Takayoshi, Thierry Giamarchi
The European Physical Journal D 76 ( 11 ) 213 2022.11
Authorship：Lead author Publisher：Springer Science and Business Media LLC
Abstract
We study the transport properties of a one-dimensional quantum system with disorder. We numerically compute the frequency dependence of the conductivity of a fermionic chain with nearest-neighbor interaction and a random chemical potential by using the Chebyshev matrix product state (CheMPS) method. As a benchmark, we investigate the noninteracting case first. Comparison with exact diagonalization and analytical solutions demonstrates that the results of CheMPS are reliable over a wide range of frequencies. We then calculate the dynamical conductivity spectra of the interacting system for various values of the interaction and disorder strengths. In the high-frequency regime, the conductivity decays as a power law, with an interaction-dependent exponent. This behavior is qualitatively consistent with the bosonized field theory predictions, although the numerical evaluation of the exponent shows deviations from the analytically expected values. We also compute the characteristic pinning frequency at which a peak in the conductivity appears. We confirm that it is directly related to the inverse of the localization length, even in the interacting case. We demonstrate that the localization length follows a power law of the disorder strength with an exponent dependent on the interaction, and find good quantitative agreement with the field theory predictions. In the low-frequency regime, we find a behavior consistent with the one of the noninteracting system $$\omega ^{2}(\ln \omega )^{2}$$ independently of the interaction. We discuss the consequences of our finding for experiments in cold atomic gases.
Graphical abstractDOI： 10.1140/epjd/s10053-022-00524-1
Other Link： https://link.springer.com/article/10.1140/epjd/s10053-022-00524-1/fulltext.html
-
Second-order magnetic responses in quantum magnets: Magnetization under ac magnetic fields Reviewed International coauthorship
Tatsuya Kaneko, Yuta Murakami, Shintaro Takayoshi, Andrew J. Millis
Physical Review B 105 ( 19 ) 195126 2022.5
Publisher：American Physical Society (APS)
We investigate second-order magnetic responses of quantum magnets against ac magnetic fields. We focus on the case where the z component of the spin is conserved in the unperturbed Hamiltonian and the driving field is applied in the xy plane. We find that linearly polarized driving fields induce a second-harmonic response, while circularly polarized fields generate only a zero-frequency response, leading to a magnetization with a direction determined by the helicity. Employing an unbiased numerical method, we demonstrate the nonlinear magnetic effect driven by the circularly polarized field in the XXZ model and show that the magnitude of the magnetization can be predicted by the dynamical spin structure factor in the linear response regime.
DOI： 10.1103/physrevb.105.195126
Other Link： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevB.105.195126/fulltext
-
Exploring nonequilibrium phases of photo-doped Mott insulators with generalized Gibbs ensembles Reviewed International coauthorship
Yuta Murakami, Shintaro Takayoshi, Tatsuya Kaneko, Zhiyuan Sun, Denis Golež, Andrew J. Millis, Philipp Werner
Communications Physics 5 ( 1 ) 23 2022.1
Publisher：Springer Science and Business Media LLC
Many experiments show that strong excitations of correlated quantum materials can cause non-thermal phases without equilibrium analogues. Understanding the origin and properties of these nonequilibrium states has been challenging due to the limitations of theoretical methods for nonequilibrium strongly correlated systems. In this work, we introduce a generalized Gibbs ensemble description that enables a systematic analysis of the long-time behavior of photo-doped states in Mott insulators based on equilibrium methods. We demonstrate the power of the method by mapping out the nonequilibrium phase diagram of the one-dimensional extended Hubbard model, which features η-pairing and charge density wave phases in a wide photo-doping range. We furthermore clarify that the peculiar kinematics of photo-doped carriers, and the interaction between them, play an essential role in the formation of these non-thermal phases. Our results establish a new path for the systematic analysis of nonequilibrium strongly correlated systems.
DOI： 10.1038/s42005-021-00799-7
Other Link： https://www.nature.com/articles/s42005-021-00799-7
-
Solitonic excitations in the Ising anisotropic chain BaCo2V2O8 under large transverse magnetic field Reviewed International coauthorship
Quentin Faure, Shintaro Takayoshi, Béatrice Grenier, Sylvain Petit, Stéphane Raymond, Martin Boehm, Pascal Lejay, Thierry Giamarchi, and Virginie Simonet
Physical Review Research 3 ( 4 ) 043227 2021.12
Publisher：American Physical Society (APS)
DOI： https://doi.org/10.1103/PhysRevResearch.3.043227
Other Link： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevResearch.3.043227/fulltext
-
Nonadiabatic nonlinear optics and quantum geometry - Application to the twisted Schwinger effect Reviewed International coauthorship
Shintaro Takayoshi, Jianda Wu, Takashi Oka
SciPost Physics 11 ( 4 ) 075 2021.10
Authorship：Lead author Publisher：SCIPOST FOUNDATION
We study the tunneling mechanism of nonlinear optical processes in solids induced by strong coherent laser fields. The theory is based on an extension of the Landau-Zener model with nonadiabatic geometric effects. In addition to the rectification effect known previously, we find two effects, namely perfect tunneling and counterdiabaticity at fast sweep speed. We apply this theory to the twisted Schwinger effect, i.e., nonadiabatic pair production of particles by rotating electric fields, and find a nonperturbative generation mechanism of the opto-valley polarization and photo-current in Dirac and Weyl fermions.
-
Scanning Tunneling Microscopy as a Single Majorana Detector of Kitaev's Chiral Spin Liquid Reviewed
Masafumi Udagawa, Shintaro Takayoshi, Takashi Oka
Physical Review Letters 126 ( 12 ) 127201 2021.3
Joint Work
Publisher：AMER PHYSICAL SOC
We propose a local detection scheme for the Majorana zero mode (MZM) carried by a vison in Kitaev's chiral spin liquid (CSL) using scanning tunneling microscopy (STM). The STM introduces a single Majorana into the system through hole-charge injection and the Majorana interacts with the MZM to form a stable composite object. We derive the exact analytical expression of single-hole Green's function in the Mott insulating limit of Kitaev's model, and show that the differential conductance has split peaks, as a consequence of resonant tunneling through the vison-hole composite. The peak splitting turns out comparable to the Majorana gap in CSL, well within the reach of experimental observation.
DOI： 10.1103/PhysRevLett.126.127201
Other Link： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevLett.126.127201/fulltext
-
Diagrammatic study of optical excitations in correlated systems Reviewed International coauthorship
Olivier Simard, Shintaro Takayoshi, Philipp Werner
Physical Review B 103 ( 10 ) 104415 2021.3
Joint Work
Publisher：AMER PHYSICAL SOC
The optical conductivity contains relevant information on the properties of correlated electron systems. In infinite dimensions, where dynamical mean field theory becomes exact, vertex corrections can be neglected and the conductivity computed from particle-hole bubbles. An interesting question concerns the nature and effect of the most relevant vertex corrections in finite-dimensional systems. A recent numerical study showed that the dominant vertex correction near an ordering instability with wave vector pi comes from a vertical ladder, analogous to the Maki-Thompson diagram. Since the random phase approximation version of this ladder diagram, dubbed pi-ton, can be easily evaluated, this suggests a simple procedure for incorporating antiferro-magnetic or charge density wave fluctuations into dynamical mean field estimates of the optical conductivity and related susceptibilities. We implement this procedure for the half-filled Hubbard model, considering the pi-ton, a double-ladder extension of the pi-ton and Aslamazov-Larkin-type diagrams, and reveal the spectral signatures of these vertex corrections.
DOI： 10.1103/PhysRevB.103.104415
Other Link： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevB.103.104415/fulltext
-
High-harmonic generation in one-dimensional Mott insulators Reviewed International coauthorship
Yuta Murakami, Shintaro Takayoshi, Akihisa Koga, Philipp Werner
Physical Review B 103 ( 3 ) 035110 2021.1
Joint Work
Publisher：AMER PHYSICAL SOC
We study high-harmonic generation (HHG) in the one-dimensional Hubbard model in order to understand its relation to elementary excitations as well as the similarities and differences to semiconductors. The simulations are based on the infinite time-evolving block decimation (iTEBD) method and exact diagonalization. We clarify that the HHG originates from the doublon-holon recombination, and the scaling of the cutoff frequency is consistent with a linear dependence on the external field. We demonstrate that the subcycle features of the HHG can be reasonably described by a phenomenological three step model for a doublon-holon pair. We argue that the HHG in the one-dimensional Mott insulator is closely related to the dispersion of the doublon-holon pair with respect to its relative momentum, which is not necessarily captured by the single-particle spectrum due to the many-body nature of the elementary excitations. For the comparison to semiconductors, we introduce effective models obtained from the Schrieffer-Wolff transformation, i.e., a strong-coupling expansion, which allows us to disentangle the different processes involved in the Hubbard model: intraband dynamics of doublons and holons, interband dipole excitations, and spin exchanges. These demonstrate the formal similarity of the Mott system to the semiconductor models in the dipole gauge, and reveal that the spin dynamics, which does not directly affect the charge dynamics, can reduce the HHG intensity. We also show that the long-range component of the intraband dipole moment has a substantial effect on the HHG intensity, while the correlated hopping terms for the doublons and holons essentially determine the shape of the HHG spectrum. A new numerical method to evaluate single-particle spectra within the iTEBD method is also introduced.
DOI： 10.1103/PhysRevB.103.035110
Other Link： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevB.103.035110/fulltext
-
Optomagnonic Barnett effect Reviewed
Kouki Nakata, Shintaro Takayoshi
Physical Review B 102 ( 9 ) 094417 2020.9
-
Ultrafast nonequilibrium evolution of excitonic modes in semiconductors Reviewed International coauthorship
Yuta Murakami, Michael Schueler, Shintaro Takayoshi, Philipp Werner
Physical Review B 101 ( 3 ) 035203 2020.1
Joint Work
Publisher：AMER PHYSICAL SOC
We study the time evolution of excitonic states after photoexcitation in the one-dimensional spinless extended Falicov-Kimball model. Several numerical methods are employed and benchmarked against each other: time-dependent mean-field simulations, the second-Born approximation (2BA) within the Kadanoff-Baym formalism, the generalized Kadanoff-Baym ansatz (GKBA) implemented with the 2BA, and the infinite time-evolving block decimation (iTEBD) method. It is found that the GKBA gives the best agreement with iTEBD and captures the relevant physics. Excitations to the particle-hole continuum and resonant excitations of the equilibrium exciton result in a qualitatively different dynamics. In the former case, the exciton binding energy remains positive and the frequency of the corresponding coherent oscillations is smaller than the band gap. On the other hand, resonant excitations trigger a collective mode whose frequency is larger than the band gap. We discuss the origin of these different behaviors by evaluating the nonequilibrium susceptibility using the nonthermal distribution and a random phase approximation. The peculiar mode with frequency larger than the band gap is associated with a partial population inversion with a sharp energy cutoff. We also discuss the effects of the cooling by a phonon bath. We demonstrate the real-time development of coherence in the polarization, which indicates excitonic condensation out of equilibrium.
DOI： 10.1103/PhysRevB.101.035203
Other Link： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevB.101.035203/fulltext
-
Laser control of magnonic topological phases in antiferromagnets Reviewed International coauthorship
Kouki Nakata, Se Kwon Kim, Shintaro Takayoshi
Physical Review B 100 ( 1 ) 014421 2019.7
Joint Work
Authorship：Last author Publisher：AMER PHYSICAL SOC
We study the laser control of magnon topological phases induced by the Aharonov-Casher effect in insulating antiferromagnets (AFs). Since the laser electric field can be considered as a time-periodic perturbation, we apply the Floquet theory and perform the inverse frequency expansion by focusing on the high frequency region. Using the obtained effective Floquet Hamiltonian, we study nonequilibrium magnon dynamics away from the adiabatic limit and its effect on topological phenomena. We show that a linearly polarized laser can generate helical edge magnon states and induce the magnonic spin Nernst effect, whereas a circularly polarized laser can generate chiral edge magnon states and induce the magnonic thermal Hall effect. In particular, in the latter, we find that the direction of the magnon chiral edge modes and the resulting thermal Hall effect can be controlled by the chirality of the circularly polarized laser through the change from the left-circular to the right-circular polarization. Our results thus provide a handle to control and design magnon topological properties in the insulating AF.
DOI： 10.1103/PhysRevB.100.014421
Other Link： https://link.aps.org/article/10.1103/PhysRevB.100.014421
-
Tomonaga-Luttinger Liquid Spin Dynamics in the Quasi-One-Dimensional Ising-Like Antiferromagnet BaCo2V2O8 Reviewed International coauthorship
Quentin Faure, Shintaro Takayoshi, Virginie Simonet, Beatrice Grenier, Martin Mansson, Jonathan S. White, Gregory S. Tucker, Christian Ruegg, Pascal Lejay, Thierry Giamarchi, Sylvain Petit
Physical Review Letters 123 ( 2 ) 027204 2019.7
Joint Work
Authorship：Corresponding author Publisher：AMER PHYSICAL SOC
Combining inelastic neutron scattering and numerical simulations, we study the quasi-one-dimensional Ising anisotropic quantum antiferromagnet BaCo2V2O8 in a longitudinal magnetic field. This material shows a quantum phase transition from a Neel ordered phase at zero field to a longitudinal incommensurate spin density wave at a critical magnetic field of 3.8 T. Concomitantly, the excitation gap almost closes and a fundamental reconfiguration of the spin dynamics occurs. These experimental results are well described by the universal Tomonaga-Luttinger liquid theory developed for interacting spinless fermions in one dimension. We especially observe the rise of mainly longitudinal excitations, a hallmark of the unconventional low-field regime in Ising-like quantum antiferromagnetic chains.
DOI： 10.1103/PhysRevLett.123.027204
Other Link： https://link.aps.org/article/10.1103/PhysRevLett.123.027204
-
High-harmonic generation in quantum spin systems Reviewed International coauthorship
Shintaro Takayoshi, Yuta Murakami, Philipp Werner
Physical Review B 99 ( 18 ) 184303 2019.5
Joint Work
Authorship：Lead author Publisher：AMER PHYSICAL SOC
We theoretically study the high-harmonic generation (HHG) in one-dimensional spin systems. While in electronic systems the driving by ac electric fields produces radiation from the dynamics of excited charges, we consider here the situation where spin systems excited by a magnetic field pulse generate radiation via a time-dependent magnetization. Specifically, we study the magnetic dipole radiation in two types of ferromagnetic spin chain models, the Ising model with static longitudinal field and the XXZ model, and reveal the structure of the spin HHG and its relation to spin excitations. For weak laser amplitude, a peak structure appears which can be explained by time-dependent perturbation theory. With increasing amplitude, plateaus with well-defined cutoff energies emerge. In the Ising model with longitudinal field, the thresholds of the multiple plateaus in the radiation spectra can be explained by the annihilation of multiple magnons. In the XXZ model, which retains the Z(2) symmetry, the laser magnetic field can induce a phase transition of the ground state when it exceeds a critical value, which results in a drastic change of the spin excitation character. As a consequence, the first cutoff energy in the HHG spectrum changes from a single-magnon to a two-magnon energy at this transition. Our results demonstrate the possibility of generating high-harmonic radiation from magnetically ordered materials and the usefulness of high-harmonic signals for extracting information on the spin excitation spectrum.
DOI： 10.1103/PhysRevB.99.184303
Other Link： https://link.aps.org/article/10.1103/PhysRevB.99.184303
-
Topological transition between competing orders in quantum spin chains Reviewed
Shintaro Takayoshi, Shunsuke C. Furuya, Thierry Giamarchi
Physical Review B 98 ( 18 ) 2018.11
-
Topological quantum phase transition in the Ising-like antiferromagnetic spin chain BaCo2V2O8 Reviewed International coauthorship
Quentin Faure, Shintaro Takayoshi, Sylvain Petit, Virginie Simonet, Stephane Raymond, Louis-Pierre Regnault, Martin Boehm, Jonathan S. White, Martin Mansson, Christian Rueegg, Pascal Lejay, Benjamin Canals, Thomas Lorenz, Shunsuke C. Furuya, Thierry Giamarchi, Beatrice Grenier
Nature Physics 14 ( 7 ) 716 - 722 2018.5
Joint Work
-
Field theory of symmetry-protected valence bond solid states in (2+1) dimensions Reviewed International coauthorship
Shintaro Takayoshi, Pierre Pujol, Akihiro Tanaka
Physical Review B 94 ( 23 ) 235159 2016.12