Quantum many-body spin ratchets

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Zadnik, Lenart, Ljubotina, Marko, Krajnik, Žiga, Ilievski, Enej, Prosen, Tomaž
Format: Preprint
Veröffentlicht: 2024
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866908370819088384
author Zadnik, Lenart
Ljubotina, Marko
Krajnik, Žiga
Ilievski, Enej
Prosen, Tomaž
author_facet Zadnik, Lenart
Ljubotina, Marko
Krajnik, Žiga
Ilievski, Enej
Prosen, Tomaž
contents Introducing a class of SU(2) invariant quantum unitary circuits generating chiral transport, we examine the role of broken space-reflection and time-reversal symmetries on spin transport properties. Upon adjusting parameters of local unitary gates, the dynamics can be either chaotic or integrable. The latter corresponds to a generalization of the space-time discretized (Trotterized) higher-spin quantum Heisenberg chain. We demonstrate that breaking of space-reflection symmetry results in a drift in the dynamical spin susceptibility. Remarkably, we find a universal drift velocity given by a simple formula which, at zero average magnetization, depends only on the values of SU(2) Casimir invariants associated with local spins. In the integrable case, the drift velocity formula is confirmed analytically based on the exact solution of thermodynamic Bethe ansatz equations. Finally, by inspecting the large fluctuations of the time-integrated current between two halves of the system in stationary maximum-entropy states, we demonstrate violation of the Gallavotti-Cohen symmetry, implying that such states cannot be regarded as equilibrium ones. We show that the scaled cumulant generating function of the time-integrated current instead obeys a generalized fluctuation relation.
format Preprint
id arxiv_https___arxiv_org_abs_2406_01571
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Quantum many-body spin ratchets
Zadnik, Lenart
Ljubotina, Marko
Krajnik, Žiga
Ilievski, Enej
Prosen, Tomaž
Statistical Mechanics
Quantum Physics
Introducing a class of SU(2) invariant quantum unitary circuits generating chiral transport, we examine the role of broken space-reflection and time-reversal symmetries on spin transport properties. Upon adjusting parameters of local unitary gates, the dynamics can be either chaotic or integrable. The latter corresponds to a generalization of the space-time discretized (Trotterized) higher-spin quantum Heisenberg chain. We demonstrate that breaking of space-reflection symmetry results in a drift in the dynamical spin susceptibility. Remarkably, we find a universal drift velocity given by a simple formula which, at zero average magnetization, depends only on the values of SU(2) Casimir invariants associated with local spins. In the integrable case, the drift velocity formula is confirmed analytically based on the exact solution of thermodynamic Bethe ansatz equations. Finally, by inspecting the large fluctuations of the time-integrated current between two halves of the system in stationary maximum-entropy states, we demonstrate violation of the Gallavotti-Cohen symmetry, implying that such states cannot be regarded as equilibrium ones. We show that the scaled cumulant generating function of the time-integrated current instead obeys a generalized fluctuation relation.
title Quantum many-body spin ratchets
topic Statistical Mechanics
Quantum Physics
url https://arxiv.org/abs/2406.01571