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

arXiv:1302.2075 · Physical Review E

Matrix-valued Boltzmann equation for the nonintegrable Hubbard chain

Martin L. R. Fürst, Christian B. Mendl, Herbert E. Spohn

Published Jul 8, 2013• 26 citations
arXivHTMLPDF

Abstract

The standard Fermi-Hubbard chain becomes nonintegrable by adding to the nearest neighbor hopping additional longer range hopping amplitudes. We assume that the quartic interaction is weak and investigate numerically the dynamics of the chain on the level of the Boltzmann type kinetic equation. Only the spatially homogeneous case is considered. We observe that the huge degeneracy of stationary states in the case of nearest neighbor hopping is lost and the convergence to the thermal Fermi-Dirac distribution is restored. The convergence to equilibrium is exponentially fast. However for small next-nearest neighbor hopping amplitudes one has a rapid relaxation towards the manifold of quasistationary states and slow relaxation to the final equilibrium state.

DOI
10.1103/physreve.88.012108

Related papers

Matrix-valued Boltzmann equation for the Hubbard chain

Martin L. R. Fürst, Christian B. Mendl, Herbert E. Spohn

We study, both analytically and numerically, the Boltzmann transport equation for the Hubbard chain with nearest-neighbor hopping and spatially homogeneous initial condition. The time-dependent Wigner function is matrix-valued because of spin. The H theorem holds. The nearest-neighbor chain is integrable, which, on the kinetic level, is reflected by infinitely many additional conservation laws and linked to the fact that there are also nonthermal stationary states. We characterize all stationary solutions. Numerically, we observe an exponentially fast convergence to stationarity and investigate the convergence rate in dependence on the initial conditions.

arXiv:1207.6926•Physical Review E•Sep 18, 2012•31 citations

Dynamics of the Bose-Hubbard chain for weak interactions

Martin L. R. Fürst, Christian B. Mendl, Herbert E. Spohn

We study the Boltzmann transport equation for the Bose-Hubbard chain in the kinetic regime. The time-dependent Wigner function is matrix-valued with odd dimension due to integer spin. For nearest neighbor hopping only, there are infinitely many additional conservation laws and nonthermal stationary states. Adding longer-range hopping amplitudes entails exclusively thermal equilibrium states. Especially for small next-nearest neighbor hopping amplitudes, we observe prethermalization with two time scales, which can be related to the relative strength of the nearest and next-nearest hopping. We provide a derivation of the Boltzmann equation based on the Hubbard Hamiltonian, including general interactions beyond on-site, and illustrate the results by numerical simulations.

arXiv:1312.6737•Physical Review B•Apr 30, 2014•1 citation

Thermalization rates in the one-dimensional Hubbard model with next-to-nearest neighbor hopping

Fabian Biebl, Stefan K. Kehrein

We consider a fermionic Hubbard chain with an additional next-to-nearest neighbor hopping term. We study the thermalization rates of the quasimomentum distribution function within a quantum Boltzmann equation approach. We find that the thermalization rates are proportional to the square of the next-to-nearest neighbor hopping: Even weak next-to-nearest neighbor hopping in addition to nearest neighbor hopping leads to thermalization in a two-particle scattering quantum Boltzmann equation in one dimension. We also investigate the temperature dependence of the thermalization rates, which away from half filling become exponentially small for small temperature of the final thermalized distribution.

arXiv:1607.07115•Physical review. B./Physical review. B•Mar 17, 2017•21 citations

Boltzmann-type approach to transport in weakly interacting one-dimensional fermionic systems

Christian Bartsch, Jochen Gemmer B

We investigate transport properties of one-dimensional fermionic tight binding models featuring nearest and next-nearest neighbor hopping, where the fermions are additionally subject to a weak short range mutual interaction. To this end we employ a pertinent approach which allows for a mapping of the underlying Schrödinger dynamics onto an adequate linear quantum Boltzmann equation. This approach is based on a suitable projection operator method. From this Boltzmann equation we are able to numerically obtain diffusion coefficients in the case of nonvanishing next-nearest neighbor hopping, i.e., the nonintegrable case, whereas the diffusion coefficient diverges without next-nearest neighbor hopping. For the latter case we analytically investigate the decay behavior of the current with the result that arbitrarily small parts of the current relax arbitrarily slowly which suggests anomalous diffusive transport behavior within the scope of our approach.

arXiv:1203.4973•Physical Review E•Apr 4, 2012•2 citations

Thermalization in one-dimensional quantum-many-body systems

Fabian Biebl

We consider the thermalization of the momentum distribution in two one-dimensional models. The first one is the integrable Hubbard model with an additional integrability breaking term in the Hamiltonian, which is a next-to-nearest-neighbor hopping term. This has been previously investigated by Fürst et al. (PRE 86:031122, 2012; PRE 88:012108, 2013). They considered several initial quasiparticle momentum distributions and their relaxation times for different strengths of the next-to-nearest-neighbor hopping amplitude. We find the dependence of the thermalization rates on the model parameters, on the filling and on temperature for any initial quasiparticle momentum distribution in the regime of small integrability breaking using a Boltzmann equation. The second model is an effective model describing a chain of manganite octahedra. There, we investigate a the temperature dependence of the relaxation rates for reasonable choices of the model parameters and the filling.

•Jan 1, 2017•1 citation

Quantum quench dynamics of the Jaynes-Cummings-Hubbard model with weak nearest-neighbor hopping

Qing Li, Jin-Lou Ma, Tong Huang +3 more

Motivated by the nonequilibrium dynamics experiment, we study the quantum quench dynamics of the JCH model with weak nearest-neighbor hopping strength by exact diagonalization. One of the crucial insights is to focus on the comparison between the time-averaged density matrix and the canonical ensemble in a wide range of values for the coupling strength between the cavity and the atom, and significant differences are found. Thus, this phenomenon can be used to infer that the system with weak nearest-neighbor hopping strength may be integrable. In order to verify our prediction, we perform the level spacing distribution of the system and find that they conform with the characteristics of the integrable system. Further, a nearly integrable system is presented by removing the degenerate energy level and fitting Brody distribution. Besides, the evolution of the momentum distribution functions of the photon and the equilibrium value predicted by the canonical ensemble are followed, which demonstrates that the system cannot be thermalized. Finally, the way how the system avoids thermalization is also discussed by the finite-size scaling of the fluctuations of the diagonal and the off-diagonal matrix elements.

Europhysics Letters (EPL)•Apr 1, 2021•6 citations
The standard Fermi-Hubbard chain becomes nonintegrable by adding to the nearest neighbor hopping additional longer range hopping amplitudes. We assume that the quartic interaction is weak and investigate numerically the dynamics of the chain on the level of the Boltzmann type kinetic equation. Only the spatially homogeneous case is considered. We observe that the huge degeneracy of stationary states in the case of nearest neighbor hopping is lost and the convergence to the thermal Fermi-Dirac distribution is restored. The convergence to equilibrium is exponentially fast. However for small next-nearest neighbor hopping amplitudes one has a rapid relaxation towards the manifold of quasistationary states and slow relaxation to the final equilibrium state.
We study, both analytically and numerically, the Boltzmann transport equation for the Hubbard chain with nearest-neighbor hopping and spatially homogeneous initial condition. The time-dependent Wigner function is matrix-valued because of spin. The H theorem holds. The nearest-neighbor chain is integrable, which, on the kinetic level, is reflected by infinitely many additional conservation laws and linked to the fact that there are also nonthermal stationary states. We characterize all stationary solutions. Numerically, we observe an exponentially fast convergence to stationarity and investigate the convergence rate in dependence on the initial conditions.
We study the Boltzmann transport equation for the Bose-Hubbard chain in the kinetic regime. The time-dependent Wigner function is matrix-valued with odd dimension due to integer spin. For nearest neighbor hopping only, there are infinitely many additional conservation laws and nonthermal stationary states. Adding longer-range hopping amplitudes entails exclusively thermal equilibrium states. Especially for small next-nearest neighbor hopping amplitudes, we observe prethermalization with two time scales, which can be related to the relative strength of the nearest and next-nearest hopping. We provide a derivation of the Boltzmann equation based on the Hubbard Hamiltonian, including general interactions beyond on-site, and illustrate the results by numerical simulations.
We consider a fermionic Hubbard chain with an additional next-to-nearest neighbor hopping term. We study the thermalization rates of the quasimomentum distribution function within a quantum Boltzmann equation approach. We find that the thermalization rates are proportional to the square of the next-to-nearest neighbor hopping: Even weak next-to-nearest neighbor hopping in addition to nearest neighbor hopping leads to thermalization in a two-particle scattering quantum Boltzmann equation in one dimension. We also investigate the temperature dependence of the thermalization rates, which away from half filling become exponentially small for small temperature of the final thermalized distribution.
We investigate transport properties of one-dimensional fermionic tight binding models featuring nearest and next-nearest neighbor hopping, where the fermions are additionally subject to a weak short range mutual interaction. To this end we employ a pertinent approach which allows for a mapping of the underlying Schrödinger dynamics onto an adequate linear quantum Boltzmann equation. This approach is based on a suitable projection operator method. From this Boltzmann equation we are able to numerically obtain diffusion coefficients in the case of nonvanishing next-nearest neighbor hopping, i.e., the nonintegrable case, whereas the diffusion coefficient diverges without next-nearest neighbor hopping. For the latter case we analytically investigate the decay behavior of the current with the result that arbitrarily small parts of the current relax arbitrarily slowly which suggests anomalous diffusive transport behavior within the scope of our approach.
We consider the thermalization of the momentum distribution in two one-dimensional models. The first one is the integrable Hubbard model with an additional integrability breaking term in the Hamiltonian, which is a next-to-nearest-neighbor hopping term. This has been previously investigated by Fürst et al. (PRE 86:031122, 2012; PRE 88:012108, 2013). They considered several initial quasiparticle momentum distributions and their relaxation times for different strengths of the next-to-nearest-neighbor hopping amplitude. We find the dependence of the thermalization rates on the model parameters, on the filling and on temperature for any initial quasiparticle momentum distribution in the regime of small integrability breaking using a Boltzmann equation. The second model is an effective model describing a chain of manganite octahedra. There, we investigate a the temperature dependence of the relaxation rates for reasonable choices of the model parameters and the filling.
Motivated by the nonequilibrium dynamics experiment, we study the quantum quench dynamics of the JCH model with weak nearest-neighbor hopping strength by exact diagonalization. One of the crucial insights is to focus on the comparison between the time-averaged density matrix and the canonical ensemble in a wide range of values for the coupling strength between the cavity and the atom, and significant differences are found. Thus, this phenomenon can be used to infer that the system with weak nearest-neighbor hopping strength may be integrable. In order to verify our prediction, we perform the level spacing distribution of the system and find that they conform with the characteristics of the integrable system. Further, a nearly integrable system is presented by removing the degenerate energy level and fitting Brody distribution. Besides, the evolution of the momentum distribution functions of the photon and the equilibrium value predicted by the canonical ensemble are followed, which demonstrates that the system cannot be thermalized. Finally, the way how the system avoids thermalization is also discussed by the finite-size scaling of the fluctuations of the diagonal and the off-diagonal matrix elements.