Polynomial-time thermalization and Gibbs sampling from system-bath couplings

Fuente: arXiv
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Main Authors: Slezak, Samuel, Scandi, Matteo, Alhambra, Álvaro M., França, Daniel Stilck, Rouzé, Cambyse
Format: Preprint
Published: 2026
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author Slezak, Samuel
Scandi, Matteo
Alhambra, Álvaro M.
França, Daniel Stilck
Rouzé, Cambyse
author_facet Slezak, Samuel
Scandi, Matteo
Alhambra, Álvaro M.
França, Daniel Stilck
Rouzé, Cambyse
contents Many physical phenomena, including thermalization in open quantum systems and quantum Gibbs sampling, are modeled by Lindbladians approximating a system weakly coupled to a bath. Understanding the convergence speed of these Lindbladians to their steady states is crucial for bounding algorithmic runtimes and thermalization timescales. We study two such families of processes: one characterizing a repeated-interaction Gibbs sampling algorithm, and another modeling open many-body quantum thermalization. We prove that both converge in polynomial time for several non-commuting systems, including high-temperature local lattices, weakly interacting fermions, and 1D spin chains. These results demonstrate that simple dissipative quantum algorithms can prepare complex Gibbs states and that Lindblad dynamics accurately capture thermal relaxation. Our proofs rely on a novel technical result that extrapolates spectral gap lower bounds from quasi-local Lindbladians to the non-local generators governing these dynamics.
format Preprint
id arxiv_https___arxiv_org_abs_2601_16154
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Polynomial-time thermalization and Gibbs sampling from system-bath couplings
Slezak, Samuel
Scandi, Matteo
Alhambra, Álvaro M.
França, Daniel Stilck
Rouzé, Cambyse
Quantum Physics
Many physical phenomena, including thermalization in open quantum systems and quantum Gibbs sampling, are modeled by Lindbladians approximating a system weakly coupled to a bath. Understanding the convergence speed of these Lindbladians to their steady states is crucial for bounding algorithmic runtimes and thermalization timescales. We study two such families of processes: one characterizing a repeated-interaction Gibbs sampling algorithm, and another modeling open many-body quantum thermalization. We prove that both converge in polynomial time for several non-commuting systems, including high-temperature local lattices, weakly interacting fermions, and 1D spin chains. These results demonstrate that simple dissipative quantum algorithms can prepare complex Gibbs states and that Lindblad dynamics accurately capture thermal relaxation. Our proofs rely on a novel technical result that extrapolates spectral gap lower bounds from quasi-local Lindbladians to the non-local generators governing these dynamics.
title Polynomial-time thermalization and Gibbs sampling from system-bath couplings
topic Quantum Physics
url https://arxiv.org/abs/2601.16154