Thermodynamic phases in first detected return times of quantum many-body systems

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Walter, Benjamin, Perfetto, Gabriele, Gambassi, Andrea
Natura: Preprint
Pubblicazione: 2023
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866916715909087232
author Walter, Benjamin
Perfetto, Gabriele
Gambassi, Andrea
author_facet Walter, Benjamin
Perfetto, Gabriele
Gambassi, Andrea
contents We study the probability distribution of the first return time to the initial state of a quantum many-body system subject to global projective measurements at stroboscopic times. We show that this distribution can be mapped to a continuation of the canonical partition function of a classical spin chain with noninteracting domains at equilibrium, which is entirely characterized by the Loschmidt amplitude of the quantum many-body system. This allows us to conclude that this probability may decay either algebraically or exponentially at long times, depending on whether the spin chain displays a ferromagnetic or a paramagnetic phase. We illustrate this idea on the example of the return time of $N$ adjacent fermions in a tight-binding model, revealing a rich phase behavior, which can be tuned by scaling the probing time as a function of $N$. The analysis presented here provides an overarching understanding of many-body quantum first-detection problems in terms of equilibrium thermodynamic phases. Our theoretical predictions are in excellent agreement with exact numerical computations.
format Preprint
id arxiv_https___arxiv_org_abs_2311_05585
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Thermodynamic phases in first detected return times of quantum many-body systems
Walter, Benjamin
Perfetto, Gabriele
Gambassi, Andrea
Statistical Mechanics
Quantum Physics
We study the probability distribution of the first return time to the initial state of a quantum many-body system subject to global projective measurements at stroboscopic times. We show that this distribution can be mapped to a continuation of the canonical partition function of a classical spin chain with noninteracting domains at equilibrium, which is entirely characterized by the Loschmidt amplitude of the quantum many-body system. This allows us to conclude that this probability may decay either algebraically or exponentially at long times, depending on whether the spin chain displays a ferromagnetic or a paramagnetic phase. We illustrate this idea on the example of the return time of $N$ adjacent fermions in a tight-binding model, revealing a rich phase behavior, which can be tuned by scaling the probing time as a function of $N$. The analysis presented here provides an overarching understanding of many-body quantum first-detection problems in terms of equilibrium thermodynamic phases. Our theoretical predictions are in excellent agreement with exact numerical computations.
title Thermodynamic phases in first detected return times of quantum many-body systems
topic Statistical Mechanics
Quantum Physics
url https://arxiv.org/abs/2311.05585