45 citations · 487 across the 36 of their papers we have counts for
36 papers
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…
Spin and charge dynamics of doped one-dimensional Mott insulators
Takami Tohyama, Hiroki Maeda, Kenji Tsutsui +2
Recent angle-resolved photoemission spectroscopy (ARPES) for a newly discovered doped one-dimensional (1D) Mott insulator BaSrCuO proposed the presence of attra…
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…
Magnetic phase diagrams of the spin- Heisenberg model on a kagome-strip chain: Emergence of a Haldane phase
Katsuhiro Morita, Shigetoshi Sota, Takami Tohyama
Frustrated one-dimensional quantum spin systems are known to exhibit a variety of quantum ground states due to the effects of quantum fluctuations and frustrations. In a spin-1/2 k…
Phase transitions in the frustrated Ising ladder with stoquastic and nonstoquastic catalysts
Kabuki Takada, Shigetoshi Sota, Seiji Yunoki +3
The role of nonstoquasticity in the field of quantum annealing and adiabatic quantum computing is an actively debated topic. We study a strongly-frustrated quasi-one-dimensional qu…
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…
Resonating dimer-monomer liquid state in a magnetization plateau of a spin- kagome-strip Heisenberg chain
Katsuhiro Morita, Shigetoshi Sota, Takami Tohyama
Highly frustrated spin systems such as the kagome lattice (KL) are a treasure trove of new quantum states with large entanglements. We thus study the spin- Heisenberg…
Proximate Kitaev system for an intermediate magnetic phase in in-plane magnetic fields
Beom Hyun Kim, Shigetoshi Sota, Tomonori Shirakawa +2
Motivated by the magnetic phase transition of a proximate Kitaev system -RuCl in the presence of a magnetic field, we study the simplest but essential quantum spin model wit…
Spin Dynamics in the t-t'-J Model: Dynamical Density-Matrix Renormalization Group Study
Takami Tohyama, Shigetoshi Sota, Seiji Yunoki
The ground state of a hole-doped t-t'-J ladder with four legs favors a striped charge distribution. Spin excitation from the striped ground state is known to exhibit incommensurate…
Magnetic excitations in magnetization plateaux of a frustrated spin ladder
Kota Sasaki, Takanori Sugimoto, Shigetoshi Sota +1
Magnetization plateaux emerging in quantum spin systems due to spontaneously breaking of translational symmetry have been reported both theoretically and experimentally. The broken…
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…
Quantum annealing for systems of polynomial equations
Chia Cheng Chang, Arjun Gambhir, Travis S. Humble +1
Numerous scientific and engineering applications require numerically solving systems of equations. Classically solving a general set of polynomial equations requires iterative solv…
Ground state phase diagram of Kitaev-Heisenberg model on honeycomb-triangular lattice
Masanori Kishimoto, Katsuhiro Morita, Yukihiro Matsubayashi +3
The Kitaev-Heisenberg model defined on both honeycomb and triangular lattices has been studied intensively in recent years as a possible model to describe spin-orbital physics in i…
Dynamical DMRG study of spin and charge excitations in the four-leg t-t'-J ladder
Takami Tohyama, Michiyasu Mori, Shigetoshi Sota
The ground state of the t-t'-J ladder with four legs favors a striped charge distribution for the parameters corresponding to hole-doped cuprate superconductors. We investigate the…
Magnetization plateaus in the spin-1/2 antiferromagnetic Heisenberg model on a kagome-strip chain
K. Morita, T. Sugimoto, S. Sota +1
Spin-1/2 Heisenberg model on kagome lattice is a typical frustrated quantum spin system. A basic structure of kagome lattice is also present in kagome-strip lattice in one dimensio…
Observation of a dispersive charge mode in hole-doped cuprates using resonant inelastic x-ray scattering at the oxygen K edge
K. Ishii, T. Tohyama, S. Asano +13
We investigate electronic excitations in La2-x(Br,Sr)xCuO4 using resonant inelastic x-ray scattering (RIXS) at the oxygen K edge. RIXS spectra of the hole-doped cuprates show clear…