Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Journal of Physics Conference Series

Numerical simulations of spectroscopic properties in two-dimensional Mott insulator

Takami Tohyama, Kazuya Shinjo, Shigetoshi Sota, Kenji Tsutsui

Published Mar 1, 2022• 1 citation
Publisher

Abstract

Abstract We numerically investigate spectroscopic properties for a two-dimensional Mott insulator described by a half-filled Hubbard model on the square lattice. Firstly, we examine the spectral shape of the optical conductivity by using time-dependent density-matrix renormalization group implemented by the Legendre polynomial expansion. We find a shape peak resembling to an excitonic peak at absorption edge, whose origin is attributable to antiferromagnetic correlation in the spin background. We next investigate momentum-dependent transient charge and spin dynamics after photoirradiation by using time-dependent Lanczos-type exact diagonalization. We find a temporal oscillation in the intensity of the dynamical spin structure factor, which exhibits an antiphase behavior between, for example, two orthogonal momentum directions parallel and perpendicular to the electric field of a pump pulse. Observing such antiphase oscillations will be a big challenge for time-resolved resonant-inelastic x-ray scattering experiments.

DOI
10.1088/1742-6596/2207/1/012028

Related papers

Antiphase oscillations in the time-resolved spin structure factor of a photoexcited Mott insulator

Tsutsui Kenji, Kazuya Shinjo, Tohyama Takami

Motivated by the recent development of time-resolved resonant-inelastic x-ray scattering (TRRIXS) in photoexcited antiferromagnetic Mott insulators, we numerically investigate momentum-dependent transient spin dynamics in a half-filled Hubbard model on a square lattice. After turning off a pumping photon pulse, the intensity of a dynamical spin structure factor temporally oscillates with frequencies determined by the energy of two magnons in the antiferromagnetic Mott insulator. We find an antiphase behavior in the oscillations between two orthogonal momentum directions, parallel and perpendicular to the electric field of a pump pulse. The phase difference comes from the B1g channel of the two-magnon excitation. Observing the antiphase oscillations will be a big challenge for TRRIXS experiments when their time resolution will be improved by more than an order of magnitude.

•Mar 1, 2021•0 citations

Antiphase oscillations in the time-resolved spin structure factor of a photoexcited Mott insulator on a square lattice

Takami Tohyama, Kazuya Shinjo, Kenji Tsutsui

Abstract We investigate momentum-dependent transient spin dynamics after photoirradiation in a two-dimensional Mott insulator described by a half-filled Hubbard model on a square lattice by using a numerically exact-diagonalization technique. We find a temporal oscillation in the static spin structure factor of a <?CDATA $\sqrt {18} \times \sqrt {18} $?> 18 × 18 periodic lattice. The oscillation exhibits an antiphase behavior between, for example, two orthogonal momentum directions parallel and perpendicular to the electric field of a pump pulse. The origin of the antiphase oscillation is attributed to a photoexcited wave function that has overlap with eigenstates producing the B 1g bimagnon Raman intensity. Observing such antiphase oscillations will be a big challenge for time-resolved resonant elastic x-ray scattering experiments.

Journal of Physics Conference Series•Mar 1, 2022•1 citation

Antiphase Oscillations in the Time-Resolved Spin Structure Factor of a Photoexcited Mott Insulator

Kenji Tsutsui, Kazuya Shinjo, Takami Tohyama

Motivated by the recent development of time-resolved resonant-inelastic x-ray scattering (TRRIXS) in photoexcited antiferromagnetic Mott insulators, we numerically investigate momentum-dependent transient spin dynamics in a half-filled Hubbard model on a square lattice. After turning off a pumping photon pulse, the intensity of a dynamical spin structure factor temporally oscillates with frequencies determined by the energy of two magnons in the antiferromagnetic Mott insulator. We find an antiphase behavior in the oscillations between two orthogonal momentum directions, parallel and perpendicular to the electric field of a pump pulse. The phase difference comes from the B_{1g} channel of the two-magnon excitation. Observing the antiphase oscillations will be a big challenge for TRRIXS experiments when their time resolution will be improved by more than an order of magnitude.

arXiv:2010.06151•Physical Review Letters•Mar 25, 2021•11 citations

Theoretical Study of the Time-Resolved Spin Excitation Spectrum in the Photoexcited Mott Insulator

Kenji Tsutsui, Kazuya Shinjo, Takami Tohyama

We theoretically investigate momentum-dependent spin dynamics that evolve after pumping within a femtosecond timescale in an antiferromagnetic (AFM) Mott insulator on a square lattice. We carry out the numerically exact diagonalization techniques on 18-site cluster of a half-filled Hubbard model. We demonstrate characteristic temporal oscillations for the spin excitation spectrum: They show an antiphase behavior for two orthogonal directions in the momentum space, which are parallel and perpendicular to the electric field of a pump pulse. Decomposing the time-dependent wave function after a pump pulse with the symmetry representation, the A1 component plays a dominant role in the main peak of the spectrum. The antiphase oscillations of the peaks can be explained by the fact that the B1g Raman active state contributes the oscillation. We expect that trRIXS can detect such oscillations when its resolution is improved for a femtosecond timescale.

International Conference on Low Temperature Physics (LT)•May 22, 2023•0 citations

Density-matrix renormalization group study on optical conductivity of the two-dimensional Mott insulator

Kazuya Shinjo, Yoshiki Tamaki, Shigetoshi Sota +1 more

The real part of optical conductivity, $\text{Re}\sigma(\omega)$, of the Mott insulators has a large amount of information on how spin and charge degrees of freedom interact with each other. By using the time-dependent density-matrix renormalization group, we study $\text{Re}\sigma(\omega)$ of the two-dimensional Hubbard model on a square lattice at half filling. We find an excitonic peak at the Mott-gap edge of $\text{Re}\sigma(\omega)$ not only for the two-dimensional square lattice but also for two- and four-leg ladders. For the square lattice, however, we do not clearly find a gap between an excitonic peak and continuum band, which indicates that a bound state is not well-defined. The emergence of an excitonic peak in $\text{Re}\sigma(\omega)$ implies the formation of a spin polaron. Examining the dependence of $\text{Re}\sigma(\omega)$ on the on-site Coulomb interaction and next-nearest neighbor hoppings, we confirm that an excitonic peak is generated from a magnetic effect. Electron scattering due to an electron-phonon interaction is expected to easily suppress an excitonic peak since spectral width of an excitonic peak is very narrow. Introducing a large broadening in $\text{Re}\sigma(\omega)$ by modeling the electron-phonon coupling present in La$_{2}$CuO$_{4}$ and Nd$_{2}$CuO$_{4}$, we obtain $\text{Re}\sigma(\omega)$ comparable with experiments.

•Sep 13, 2021•0 citations

Density-matrix renormalization group study of optical conductivity of the Mott insulator for two-dimensional clusters

Kazuya Shinjo, Yoshiki Tamaki, Shigetoshi Sota +1 more

The real part of optical conductivity $\text{Re}\ensuremath{\sigma}(\ensuremath{\omega})$ of the Mott insulators has a large amount of information on how spin and charge degrees of freedom interact with each other. By using the time-dependent density-matrix renormalization group, we study $\text{Re}\ensuremath{\sigma}(\ensuremath{\omega})$ of the two-dimensional Hubbard model on a square lattice at half filling. We find an excitonic peak at the Mott-gap edge of $\text{Re}\ensuremath{\sigma}(\ensuremath{\omega})$ not only for the two-dimensional square lattice but also for two- and four-leg ladders. For the square lattice, however, we do not clearly find a gap between an excitonic peak and continuum band, which indicates that a bound state is not well defined. The emergence of an excitonic peak in $\text{Re}\ensuremath{\sigma}(\ensuremath{\omega})$ implies the formation of a spin polaron. Examining the dependence of $\text{Re}\ensuremath{\sigma}(\ensuremath{\omega})$ on the on-site Coulomb interaction and next-nearest-neighbor hoppings, we confirm that an excitonic peak is generated from a magnetic effect. Electron scattering due to an electron-phonon interaction is expected to easily suppress an excitonic peak since spectral width of an excitonic peak is very narrow. Introducing a large broadening in $\text{Re}\ensuremath{\sigma}(\ensuremath{\omega})$ by modeling the electron-phonon coupling present in ${\mathrm{La}}_{2}{\mathrm{CuO}}_{4}$ and ${\mathrm{Nd}}_{2}{\mathrm{CuO}}_{4}$, we obtain $\text{Re}\ensuremath{\sigma}(\ensuremath{\omega})$ comparable with experiments.

arXiv:2109.06226•Physical review. B./Physical review. B•Nov 19, 2021•15 citations
Abstract We numerically investigate spectroscopic properties for a two-dimensional Mott insulator described by a half-filled Hubbard model on the square lattice. Firstly, we examine the spectral shape of the optical conductivity by using time-dependent density-matrix renormalization group implemented by the Legendre polynomial expansion. We find a shape peak resembling to an excitonic peak at absorption edge, whose origin is attributable to antiferromagnetic correlation in the spin background. We next investigate momentum-dependent transient charge and spin dynamics after photoirradiation by using time-dependent Lanczos-type exact diagonalization. We find a temporal oscillation in the intensity of the dynamical spin structure factor, which exhibits an antiphase behavior between, for example, two orthogonal momentum directions parallel and perpendicular to the electric field of a pump pulse. Observing such antiphase oscillations will be a big challenge for time-resolved resonant-inelastic x-ray scattering experiments.
Motivated by the recent development of time-resolved resonant-inelastic x-ray scattering (TRRIXS) in photoexcited antiferromagnetic Mott insulators, we numerically investigate momentum-dependent transient spin dynamics in a half-filled Hubbard model on a square lattice. After turning off a pumping photon pulse, the intensity of a dynamical spin structure factor temporally oscillates with frequencies determined by the energy of two magnons in the antiferromagnetic Mott insulator. We find an antiphase behavior in the oscillations between two orthogonal momentum directions, parallel and perpendicular to the electric field of a pump pulse. The phase difference comes from the B1g channel of the two-magnon excitation. Observing the antiphase oscillations will be a big challenge for TRRIXS experiments when their time resolution will be improved by more than an order of magnitude.
Abstract We investigate momentum-dependent transient spin dynamics after photoirradiation in a two-dimensional Mott insulator described by a half-filled Hubbard model on a square lattice by using a numerically exact-diagonalization technique. We find a temporal oscillation in the static spin structure factor of a <?CDATA $\sqrt {18} \times \sqrt {18} $?> 18 × 18 periodic lattice. The oscillation exhibits an antiphase behavior between, for example, two orthogonal momentum directions parallel and perpendicular to the electric field of a pump pulse. The origin of the antiphase oscillation is attributed to a photoexcited wave function that has overlap with eigenstates producing the B 1g bimagnon Raman intensity. Observing such antiphase oscillations will be a big challenge for time-resolved resonant elastic x-ray scattering experiments.
Motivated by the recent development of time-resolved resonant-inelastic x-ray scattering (TRRIXS) in photoexcited antiferromagnetic Mott insulators, we numerically investigate momentum-dependent transient spin dynamics in a half-filled Hubbard model on a square lattice. After turning off a pumping photon pulse, the intensity of a dynamical spin structure factor temporally oscillates with frequencies determined by the energy of two magnons in the antiferromagnetic Mott insulator. We find an antiphase behavior in the oscillations between two orthogonal momentum directions, parallel and perpendicular to the electric field of a pump pulse. The phase difference comes from the B_{1g} channel of the two-magnon excitation. Observing the antiphase oscillations will be a big challenge for TRRIXS experiments when their time resolution will be improved by more than an order of magnitude.
We theoretically investigate momentum-dependent spin dynamics that evolve after pumping within a femtosecond timescale in an antiferromagnetic (AFM) Mott insulator on a square lattice. We carry out the numerically exact diagonalization techniques on 18-site cluster of a half-filled Hubbard model. We demonstrate characteristic temporal oscillations for the spin excitation spectrum: They show an antiphase behavior for two orthogonal directions in the momentum space, which are parallel and perpendicular to the electric field of a pump pulse. Decomposing the time-dependent wave function after a pump pulse with the symmetry representation, the A1 component plays a dominant role in the main peak of the spectrum. The antiphase oscillations of the peaks can be explained by the fact that the B1g Raman active state contributes the oscillation. We expect that trRIXS can detect such oscillations when its resolution is improved for a femtosecond timescale.
The real part of optical conductivity, Reσ(ω)\text{Re}\sigma(\omega)Reσ(ω), of the Mott insulators has a large amount of information on how spin and charge degrees of freedom interact with each other. By using the time-dependent density-matrix renormalization group, we study Reσ(ω)\text{Re}\sigma(\omega)Reσ(ω) of the two-dimensional Hubbard model on a square lattice at half filling. We find an excitonic peak at the Mott-gap edge of Reσ(ω)\text{Re}\sigma(\omega)Reσ(ω) not only for the two-dimensional square lattice but also for two- and four-leg ladders. For the square lattice, however, we do not clearly find a gap between an excitonic peak and continuum band, which indicates that a bound state is not well-defined. The emergence of an excitonic peak in Reσ(ω)\text{Re}\sigma(\omega)Reσ(ω) implies the formation of a spin polaron. Examining the dependence of Reσ(ω)\text{Re}\sigma(\omega)Reσ(ω) on the on-site Coulomb interaction and next-nearest neighbor hoppings, we confirm that an excitonic peak is generated from a magnetic effect. Electron scattering due to an electron-phonon interaction is expected to easily suppress an excitonic peak since spectral width of an excitonic peak is very narrow. Introducing a large broadening in Reσ(ω)\text{Re}\sigma(\omega)Reσ(ω) by modeling the electron-phonon coupling present in La2_{2}2​CuO4_{4}4​ and Nd2_{2}2​CuO4_{4}4​, we obtain Reσ(ω)\text{Re}\sigma(\omega)Reσ(ω) comparable with experiments.
The real part of optical conductivity $\text{Re}\ensuremath{\sigma}(\ensuremath{\omega})$ of the Mott insulators has a large amount of information on how spin and charge degrees of freedom interact with each other. By using the time-dependent density-matrix renormalization group, we study $\text{Re}\ensuremath{\sigma}(\ensuremath{\omega})$ of the two-dimensional Hubbard model on a square lattice at half filling. We find an excitonic peak at the Mott-gap edge of $\text{Re}\ensuremath{\sigma}(\ensuremath{\omega})$ not only for the two-dimensional square lattice but also for two- and four-leg ladders. For the square lattice, however, we do not clearly find a gap between an excitonic peak and continuum band, which indicates that a bound state is not well defined. The emergence of an excitonic peak in $\text{Re}\ensuremath{\sigma}(\ensuremath{\omega})$ implies the formation of a spin polaron. Examining the dependence of $\text{Re}\ensuremath{\sigma}(\ensuremath{\omega})$ on the on-site Coulomb interaction and next-nearest-neighbor hoppings, we confirm that an excitonic peak is generated from a magnetic effect. Electron scattering due to an electron-phonon interaction is expected to easily suppress an excitonic peak since spectral width of an excitonic peak is very narrow. Introducing a large broadening in $\text{Re}\ensuremath{\sigma}(\ensuremath{\omega})$ by modeling the electron-phonon coupling present in La2CuO4{\mathrm{La}}_{2}{\mathrm{CuO}}_{4}La2​CuO4​ and Nd2CuO4{\mathrm{Nd}}_{2}{\mathrm{CuO}}_{4}Nd2​CuO4​, we obtain $\text{Re}\ensuremath{\sigma}(\ensuremath{\omega})$ comparable with experiments.