Spectral gaps of local quantum channels in the weak-dissipation limit

Fuente: arXiv
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Main Authors: Jacoby, J. Alexander, Huse, David A., Gopalakrishnan, Sarang
Format: Preprint
Published: 2024
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author Jacoby, J. Alexander
Huse, David A.
Gopalakrishnan, Sarang
author_facet Jacoby, J. Alexander
Huse, David A.
Gopalakrishnan, Sarang
contents We consider the dynamics of generic chaotic quantum many-body systems with no conservation laws, subject to weak bulk dissipation. It was recently observed [T. Mori, arXiv:2311.10304] that the generator of these dissipative dynamics, a quantum channel $\mathcal{E}$, retains a nonzero gap as the dissipation strength $γ\to 0$ if the thermodynamic limit is taken first. We use a hydrodynamic description of operator spreading in the presence of dissipation to estimate the gap of $\mathcal{E}$ as $γ\to 0$; to calculate the operator-size distribution of the low-lying eigenmodes of $\mathcal{E}$; and to relate the gap to the long-time decay rates of autocorrelation functions under unitary dynamics. We provide a microscopic derivation of this hydrodynamic perspective for random unitary circuits. We argue that the gap in the $γ\to 0$ limit can change nonanalytically as one tunes the parameters of the unitary dynamics.
format Preprint
id arxiv_https___arxiv_org_abs_2409_17238
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Spectral gaps of local quantum channels in the weak-dissipation limit
Jacoby, J. Alexander
Huse, David A.
Gopalakrishnan, Sarang
Quantum Physics
Statistical Mechanics
Strongly Correlated Electrons
We consider the dynamics of generic chaotic quantum many-body systems with no conservation laws, subject to weak bulk dissipation. It was recently observed [T. Mori, arXiv:2311.10304] that the generator of these dissipative dynamics, a quantum channel $\mathcal{E}$, retains a nonzero gap as the dissipation strength $γ\to 0$ if the thermodynamic limit is taken first. We use a hydrodynamic description of operator spreading in the presence of dissipation to estimate the gap of $\mathcal{E}$ as $γ\to 0$; to calculate the operator-size distribution of the low-lying eigenmodes of $\mathcal{E}$; and to relate the gap to the long-time decay rates of autocorrelation functions under unitary dynamics. We provide a microscopic derivation of this hydrodynamic perspective for random unitary circuits. We argue that the gap in the $γ\to 0$ limit can change nonanalytically as one tunes the parameters of the unitary dynamics.
title Spectral gaps of local quantum channels in the weak-dissipation limit
topic Quantum Physics
Statistical Mechanics
Strongly Correlated Electrons
url https://arxiv.org/abs/2409.17238