39 citations · 190 across the 22 of their papers we have counts for
22 papers
Quantum synchronization and chimera states in a programmable quantum many-body system
Kazuya Shinjo, Kazuhiro Seki, Seiji Yunoki
Synchronization is a hallmark of collective behavior in classical nonlinear systems, yet its realization as a robust many-body phenomenon in coherent quantum systems remains largel…
Observation of Improved Accuracy over Classical Sparse Ground-State Solvers using a Quantum Computer
William Kirby, Bibek Pokharel, Javier Robledo Moreno +25
Demonstrating quantum advantage over classical algorithms for ground state energy problems is an outstanding open problem in quantum computation. We experimentally demonstrate that…
Noise-stabilized discrete time crystals on digital quantum processors
Kazuya Shinjo, Kazuhiro Seki, Seiji Yunoki
Floquet many-body phases such as discrete time crystals (DTCs) are typically fragile to imperfections, and stabilizing them on noisy quantum hardware remains a central challenge in…
Low-energy photoexcitations inside the Mott gap in doped Hubbard and t-J ladders
Sumal Chandra, Kazuya Shinjo, Shigetoshi Sota +2
We investigate changes in the optical conductivity of doped Mott insulators by tuning ultrashort pump pulses to target either the Drude or low-energy absorption regions. Using a ho…
Optical absorption activated by an ultrashort half-cycle pulse in metallic and superconducting states of the Hubbard model
Kazuya Shinjo, Shigetoshi Sota, Seiji Yunoki +1
The development of high-intensity ultrashort laser pulses unlocks the potential of pump-probe spectroscopy in sub-femtosecond timescale. Notably, subcycle pump pulses can generate…
Unveiling clean two-dimensional discrete time crystals on a digital quantum computer
Kazuya Shinjo, Kazuhiro Seki, Tomonori Shirakawa +2
In periodically driven (Floquet) systems, evolution typically results in an infinite-temperature thermal state due to continuous energy absorption over time. However, before reachi…
Keldysh crossover in one-dimensional Mott insulators
Kazuya Shinjo, Takami Tohyama
Recent advancements in pulse laser technology have facilitated the exploration of non-equilibrium spectroscopy of electronic states in the presence of strong electric fields across…
Spin loop-current textures in Hubbard models
Kazuya Shinjo, Shigetoshi Sota, Seiji Yunoki +1
The recent experimental observations of loop current in SrIrO, YBaCuO, and SrCuO have inspired a theoretical study that broadly r…
Anomalous suppression of photo-induced in-gap weight in the optical conductivity of a two-leg Hubbard ladder
Takami Tohyama, Kazuya Shinjo, Shigetoshi Sota +1
Photoinduced nonequilibrium states in the Mott insulators reflect the fundamental nature of competition between itinerancy and localization of the charge degrees of freedom. The sp…
Controlling inversion and time-reversal symmetries by subcycle pulses in the one-dimensional extended Hubbard model
Kazuya Shinjo, Shigetoshi Sota, Seiji Yunoki +1
Owning to their high controllability, laser pulses have contributed greatly to our understanding of strongly correlated electron systems. However, typical multicycle pulses do not…
Exciton-assisted low-energy magnetic excitations in a photoexcited Mott insulator on a square lattice
Kenji Tsutsui, Kazuya Shinjo, Shigetoshi Sota +1
The photoexcitation of a Mott insulator on a square lattice weakens the intensity of both single- and two-magnon excitations as observed in time-resolved resonant-inelastic X-ray s…
Glassy dynamics of the one-dimensional Mott insulator excited by a strong terahertz pulse
Kazuya Shinjo, Shigetoshi Sota, Takami Tohyama
The elucidation of nonequilibrium states in strongly correlated systems holds the key to emergence of novel quantum phases. The nonequilibrium-induced insulator-to-metal transition…
Density-matrix renormalization group study of optical conductivity of the Mott insulator for two-dimensional clusters
Kazuya Shinjo, Yoshiki Tamaki, Shigetoshi Sota +1
The real part of optical conductivity of the Mott insulators has a large amount of information on how spin and charge degrees of freedom interact with each other. B…
Effect of phase string on single-hole dynamics in the two-leg Hubbard ladder
Kazuya Shinjo, Shigetoshi Sota, Takami Tohyama
Optical measurements in doped Mott insulators have discovered the emergence of spectral weights at mid-infrared (MIR) upon chemical doping and photodoping. MIR weights may have a r…
A charge model as an effective model of one-dimensional Hubbard and extended Hubbard systems: its application to linear optical spectrum calculations in large systems based upon many-body Wannier functions
Shu Ohmura, Akira Takahashi, Kaoru Iwano +5
We propose an effective model called the "charge model", for the half-filled one-dimensional Hubbard and extended Hubbard models. In this model, spin-charge separation, which has b…
Machine Learning Phase Diagram in the Half-filled One-dimensional Extended Hubbard Model
Kazuya Shinjo, Kakeru Sasaki, Satoru Hase +4
We demonstrate that supervised machine learning (ML) with entanglement spectrum can give useful information for constructing phase diagram in the half-filled one-dimensional extend…
Characterization of photoexcited states in the half-filled one-dimensional extended Hubbard model assisted by machine learning
Kazuya Shinjo, Shigetoshi Sota, Seiji Yunoki +1
Photoinduced nonequilibrium states can provide new insight into dynamical properties of strongly correlated electron systems. One of the typical and extensively studied systems is…
Ultrafast transient interference in pump-probe spectroscopy of band and Mott insulators
Kazuya Shinjo, Takami Tohyama
Ultrafast pump-probe spectroscopy with high temporal and spectral resolutions provides new insight into ultrafast nonequilibrium phenomena. We propose that transient interference b…
Photoinduced absorptions inside the Mott gap in the two-dimensional extended Hubbard model
Kazuya Shinjo, Takami Tohyama
We theoretically investigate pump-probe optical responses in the two-dimensional extended Hubbard model describing cuprates by using a time-dependent Lanczos method. At half fillin…
Ground state properties of determined from Hamiltonian and its extensions containing Kitaev and extended Heisenberg interactions
Tsuyoshi Okubo, Kazuya Shinjo, Youhei Yamaji +4
We investigate the ground state properties of based on numerical calculations of the recently proposed {\it ab initio} Hamiltonian represented by Kitaev and ex…
Density-Matrix Renormalization Group Study of Kitaev--Heisenberg Model on a Triangular Lattice
Kazuya Shinjo, Shigetoshi Sota, Seiji Yunoki +2
We study the Kitaev--Heisenberg model on a triangular lattice by using the two-dimensional density-matrix renormalization group method. Calculating the ground-state energy and spin…
Density-Matrix Renormalization Group Study of Extended Kitaev-Heisenberg Model
Kazuya Shinjo, Shigetoshi Sota, Takami Tohyama
We study an extended Kitaev-Heisenberg model including additional anisotropic couplings by using two-dimensional density-matrix renormalization group method. Calculating the gound-…