A metronome spin stabilizes time-crystalline dynamics

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Euler, Niklas, Braemer, Adrian, Benn, Luca, Gärttner, Martin
Format: Preprint
Veröffentlicht: 2024
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866909232698228736
author Euler, Niklas
Braemer, Adrian
Benn, Luca
Gärttner, Martin
author_facet Euler, Niklas
Braemer, Adrian
Benn, Luca
Gärttner, Martin
contents We investigate a disorder-free quantum Ising chain subject to a time-periodic drive that rotates each spin by an angle $π(1-ε_i)$. In case all spins experience the same deviation $ε$ and the system is initialized in a fully polarized state, the dynamics is known to be time-crystalline: the magnetization of the system exhibits period-doubled oscillations for timescales that grow exponentially with the length of the chain. In this work, we study the effect of a deviation $ε$ that differs between spins. We find that reducing $ε$ for a single spin drastically enhances the lifetime of spatio-temporal order, suggesting the name ``metronome" spin. Employing perturbative arguments in an average Hamiltonian picture, we explain this observation for initial states with macroscopic bulk magnetization. Furthermore, in the case of random bitstring initial states, we report the enhancement of the lifetime of a topological edge mode, which can also be understood in the same picture. Finally, we discuss an altered geometry in which the metronome spin is not directly part of the chain, affecting the dynamics in different ways in the two scenarios considered. Our findings unveil the intricate dynamics that emerge in Floquet systems under the influence of a spatially varying drive, thereby uncovering new avenues for Floquet engineering.
format Preprint
id arxiv_https___arxiv_org_abs_2402_04078
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle A metronome spin stabilizes time-crystalline dynamics
Euler, Niklas
Braemer, Adrian
Benn, Luca
Gärttner, Martin
Quantum Physics
Statistical Mechanics
We investigate a disorder-free quantum Ising chain subject to a time-periodic drive that rotates each spin by an angle $π(1-ε_i)$. In case all spins experience the same deviation $ε$ and the system is initialized in a fully polarized state, the dynamics is known to be time-crystalline: the magnetization of the system exhibits period-doubled oscillations for timescales that grow exponentially with the length of the chain. In this work, we study the effect of a deviation $ε$ that differs between spins. We find that reducing $ε$ for a single spin drastically enhances the lifetime of spatio-temporal order, suggesting the name ``metronome" spin. Employing perturbative arguments in an average Hamiltonian picture, we explain this observation for initial states with macroscopic bulk magnetization. Furthermore, in the case of random bitstring initial states, we report the enhancement of the lifetime of a topological edge mode, which can also be understood in the same picture. Finally, we discuss an altered geometry in which the metronome spin is not directly part of the chain, affecting the dynamics in different ways in the two scenarios considered. Our findings unveil the intricate dynamics that emerge in Floquet systems under the influence of a spatially varying drive, thereby uncovering new avenues for Floquet engineering.
title A metronome spin stabilizes time-crystalline dynamics
topic Quantum Physics
Statistical Mechanics
url https://arxiv.org/abs/2402.04078