Quasi-Adiabatic Processing of Thermal States

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Irmejs, Reinis, Bañuls, Mari Carmen, Cirac, J. Ignacio
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908876785319936
author Irmejs, Reinis
Bañuls, Mari Carmen
Cirac, J. Ignacio
author_facet Irmejs, Reinis
Bañuls, Mari Carmen
Cirac, J. Ignacio
contents We investigate the performance of an adiabatic evolution protocol when initialized from a Gibbs state at finite temperature. Specifically, we identify the diagonality of the final state in the energy eigenbasis, as well as the difference in energy and in energy variance with respect to the ideal adiabatic limit as key benchmarks for success and introduce metrics to quantify the off-diagonal contributions. Provided these benchmarks converge to their ideal adiabatic values, we argue that thermal expectation values of observables can be recovered, in accordance with the eigenstate thermalization hypothesis. For the transverse-field Ising model, we analytically establish that these benchmarks converge polynomially in both the quasi-adiabatic evolution time $T$ and system size. We perform numerical studies on non-integrable systems and find close quantitative agreement for the off-diagonality metrics, along with qualitatively similar behavior in the energy convergence.
format Preprint
id arxiv_https___arxiv_org_abs_2505_20042
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Quasi-Adiabatic Processing of Thermal States
Irmejs, Reinis
Bañuls, Mari Carmen
Cirac, J. Ignacio
Quantum Physics
We investigate the performance of an adiabatic evolution protocol when initialized from a Gibbs state at finite temperature. Specifically, we identify the diagonality of the final state in the energy eigenbasis, as well as the difference in energy and in energy variance with respect to the ideal adiabatic limit as key benchmarks for success and introduce metrics to quantify the off-diagonal contributions. Provided these benchmarks converge to their ideal adiabatic values, we argue that thermal expectation values of observables can be recovered, in accordance with the eigenstate thermalization hypothesis. For the transverse-field Ising model, we analytically establish that these benchmarks converge polynomially in both the quasi-adiabatic evolution time $T$ and system size. We perform numerical studies on non-integrable systems and find close quantitative agreement for the off-diagonality metrics, along with qualitatively similar behavior in the energy convergence.
title Quasi-Adiabatic Processing of Thermal States
topic Quantum Physics
url https://arxiv.org/abs/2505.20042