255 citations · 1.1k across the 24 of their papers we have counts for
24 papers
Maxwell-Vlasov-Uehling-Uhlenbeck (VUU) Simulation for Coupled Laser-Electron Dynamics in a Metal Irradiated by Ultrashort Intense Laser Pulses
Mizuki Tani, Tomohito Otobe, Yasushi Shinohara +1
The description of electron-electron scattering presents challenges in the microscopic modeling of the interaction of ultrashort intense laser pulses with solids. We extend the sem…
Enhancement of Zener tunneling rate via electron-hole attraction within a time-dependent quasi-Hartree-Fock method
Yasushi Shinohara, Haruki Sanada, Katsuya Oguri
The tunneling process, a prototypical phenomenon of nonperturbative dynamics, is a natural consequence of photocarrier generation in materials irradiated by a strong laser. Common…
1-MHz operation of 1.7-cycle multiple plate compression at 35-W average output power
Takuya Okamoto, Yoji Kunihashi, Yasushi Shinohara +3
We generated 1.7-cycle and 35-J pulses at a 1-MHz repetition rate by using two-stage multiple plate continuum compression of Yb-laser pulses with 80-W average input power. By ad…
Enhanced energy deposition and carrier generation in silicon induced by two-color intense femtosecond laser pulses
Mizuki Tani, Kakeru Sasaki, Yasushi Shinohara +1
We theoretically investigate the optical energy absorption of crystalline silicon subject to dual-color femtosecond laser pulses, using the time-dependent density functional theory…
Atomic real-space perspective of light-field-driven currents in graphene
Yuya Morimoto, Yasushi Shinohara, Kenichi L. Ishikawa +1
When graphene is exposed to a strong few-cycle optical field, a directional electric current can be induced depending on the carrier-envelope phase of the field. This phenomenon ha…
Semi-classical description of electron dynamics in extended systems under intense laser fields
Mizuki Tani, Tomohito Otobe, Yasushi Shinohara +1
We propose a semi-classical approach based on the Vlasov equation to describe the time-dependent electronic dynamics in a bulk simple metal under an ultrashort intense laser pulse.…
Strong-Field Electron Dynamics in Solids
Kenichi L. Ishikawa, Yasushi Shinohara, Takeshi Sato +1
Solid-state materials have recently emerged as a new stage of strong-field physics and attosecond science. The mechanism of the electron dynamics driven by an ultrashort intense la…
Detecting electron-phonon couplings during photo-induced phase transition
Takeshi Suzuki, Yasushi Shinohara, Yangfan Lu +13
Photo-induced phase transitions have been intensively studied owing to the ability to control a material of interest in the ultrafast manner, which can induce exotic phases unable…
Asymmetric nonlinear optics of a polar chemical bond
Yuya Morimoto, Yasushi Shinohara, Mizuki Tani +3
A dielectric material's response to light is macroscopically described by electric displacement fields due to polarization and susceptibility, but the atomistic origin is light-cyc…
Gauge Invariance beyond the Electric Dipole Approximation
Ryoji Anzaki, Yasushi Shinohara, Takeshi Sato +1
We study the gauge invariance of laser-matter interaction. The velocity gauge where the vector potential is expanded to the -th order with respect to the spatial coordinate, and…
SALMON: Scalable Ab-initio Light-Matter simulator for Optics and Nanoscience
Masashi Noda, Shunsuke A. Sato, Yuta Hirokawa +15
SALMON (Scalable Ab-initio Light-Matter simulator for Optics and Nanoscience, http://salmon-tddft.jp) is a software package for the simulation of electron dynamics and optical prop…
Time-dependent Hartree-Fock study of electron-hole interaction effects on high-harmonic generation from periodic crystals
Takuya Ikemachi, Yasushi Shinohara, Takeshi Sato +3
We investigate the multielectron effects on high-harmonic generation from solid-state materials using the time-dependent Hartree-Fock theory. We find qualitative change in harmonic…
Theory for the electron excitation in dielectrics under an intense circularly polarized laser field
T. Otobe, Y. Shinohara, S. A. Sato +1
We report a Keldysh-like model for the electron transition rate in dielectrics under an intense circularly polarized laser. We assume a parabolic two-band system and the Houston fu…
Trajectory analysis of high-harmonic generation from periodic crystals
Takuya Ikemachi, Yasushi Shinohara, Takeshi Sato +3
We theoretically study high-harmonic generation (HHG) from solids driven by intense laser pulses using a one-dimensional model periodic crystal. By numerically solving the time-dep…
Reduced-Shifted Conjugate-Gradient Method for a Green's Function: Efficient Numerical Approach in a Nano-structured Superconductor
Yuki Nagai, Yasushi Shinohara, Yasunori Futamura +1
We propose the reduced-shifted Conjugate-Gradient (RSCG) method, which is numerically efficient to calculate a matrix element of a Green's function defined as a resolvent of a Hami…
Nonlinear electronic excitations in crystalline solids using meta-generalized gradient approximation and hybrid functional in time-dependent density functional theory
Shunsuke A. Sato, Yasutaka Taniguchi, Yasushi Shinohara +1
We develop numerical methods to calculate electron dynamics in crystalline solids in real-time time-dependent density functional theory employing exchange-correlation potentials wh…
Femtosecond time-resolved dynamical Franz-Keldysh effect
T. Otobe, Y. Shinohara, S. A. Sato +1
We theoretically investigate the dynamical Franz-Keldysh effect in femtosecond time resolution, that is, the time-dependent modulation of a dielectric function at around the band g…
Dielectric response of laser-excited silicon at finite electron temperature
S. A. Sato, Y. Shinohara, T. Otobe +1
We calculate the dielectric response of excited crystalline silicon in electron thermal equilibrium by adiabatic time-dependent density functional theory (TDDFT) to model the respo…
First-principles simulation of the optical response of bulk and thin-film α-quartz irradiated with an ultrashort intense laser pulse
Kyung-Min Lee, Chul Min Kim, Shunsuke A. Sato +4
A computational method based on a first-principles multiscale simulation has been used for calculating the optical response and the ablation threshold of an optical material irradi…
Dielectric response of laser-excited silicon
S. A. Sato, K. Yabana, Y. Shinohara +2
We calculate the dielectric response of crystalline silicon following irradiation by a high-intensity laser pulse, modeling the dynamics by time-dependent density functional theory…
Numerical construction of a low-energy effective Hamiltonian in a self-consistent Bogoliubov-de Gennes approach of superconductivity
Yuki Nagai, Yasushi Shinohara, Yasunori Futamura +2
We propose a fast and efficient approach for solving the Bogoliubov-de Gennes (BdG) equations in superconductivity, with a numerical matrix-size reduction procedure proposed by Sak…
Nonadiabatic generation of coherent phonons
Y. Shinohara, S. A. Sato, K. Yabana +3
The time-dependent density functional theory (TDDFT) is the leading computationally feasible theory to treat excitations by strong electromagnetic fields. Here the theory is applie…
Time-dependent density functional theory for strong electromagnetic fields in crystalline solids
K. Yabana, T. Sugiyama, Y. Shinohara +2
We apply the coupled dynamics of time-dependent density functional theory and Maxwell equations to the interaction of intense laser pulses with crystalline silicon. As a function o…
Ab initio theory of coherent phonon generation by laser excitation
Y. Shinohara, Y. Kawashita, K. Yabana +3
We show that time-dependent density functional theory (TDDFT) is applicable to coherent optical phonon generation by intense laser pulses in solids. The two mechanisms invoked in p…