Weak integrability breaking perturbations of integrable models

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Surace, Federica Maria, Motrunich, Olexei
Format: Preprint
Published: 2023
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914791135641600
author Surace, Federica Maria
Motrunich, Olexei
author_facet Surace, Federica Maria
Motrunich, Olexei
contents A quantum integrable system slightly perturbed away from integrability is typically expected to thermalize on timescales of order $τ\sim λ^{-2}$, where $λ$ is the perturbation strength. We here study classes of perturbations that violate this scaling, and exhibit much longer thermalization times $τ\sim λ^{-2\ell}$ where $\ell>1$ is an integer. Systems with these "weak integrability breaking" perturbations have an extensive number of quasi-conserved quantities that commute with the perturbed Hamiltonian up to corrections of order $λ^\ell$. We demonstrate a systematic construction to obtain families of such weak perturbations of a generic integrable model for arbitrary $\ell$. We then apply the construction to various models, including the Heisenberg, XXZ, and XYZ chains, the Hubbard model, models of spinless free fermions, and the quantum Ising chain. Our analytical framework explains the previously observed evidence of weak integrability breaking in the Heisenberg and XXZ chains under certain perturbations.
format Preprint
id arxiv_https___arxiv_org_abs_2302_12804
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Weak integrability breaking perturbations of integrable models
Surace, Federica Maria
Motrunich, Olexei
Statistical Mechanics
Quantum Gases
Strongly Correlated Electrons
Quantum Physics
A quantum integrable system slightly perturbed away from integrability is typically expected to thermalize on timescales of order $τ\sim λ^{-2}$, where $λ$ is the perturbation strength. We here study classes of perturbations that violate this scaling, and exhibit much longer thermalization times $τ\sim λ^{-2\ell}$ where $\ell>1$ is an integer. Systems with these "weak integrability breaking" perturbations have an extensive number of quasi-conserved quantities that commute with the perturbed Hamiltonian up to corrections of order $λ^\ell$. We demonstrate a systematic construction to obtain families of such weak perturbations of a generic integrable model for arbitrary $\ell$. We then apply the construction to various models, including the Heisenberg, XXZ, and XYZ chains, the Hubbard model, models of spinless free fermions, and the quantum Ising chain. Our analytical framework explains the previously observed evidence of weak integrability breaking in the Heisenberg and XXZ chains under certain perturbations.
title Weak integrability breaking perturbations of integrable models
topic Statistical Mechanics
Quantum Gases
Strongly Correlated Electrons
Quantum Physics
url https://arxiv.org/abs/2302.12804