Emergent strong zero mode through local Floquet engineering

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Mukherjee, Bhaskar, Melendrez, Ronald, Szyniszewski, Marcin, Changlani, Hitesh J., Pal, Arijeet
Format: Preprint
Veröffentlicht: 2023
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866910333122117632
author Mukherjee, Bhaskar
Melendrez, Ronald
Szyniszewski, Marcin
Changlani, Hitesh J.
Pal, Arijeet
author_facet Mukherjee, Bhaskar
Melendrez, Ronald
Szyniszewski, Marcin
Changlani, Hitesh J.
Pal, Arijeet
contents Periodically driven quantum systems host exotic phenomena which often do not have any analog in undriven systems. Floquet prethermalization and dynamical freezing of certain observables, via the emergence of conservation laws, are realized by controlling the drive frequency. These dynamical regimes can be leveraged to construct quantum memories and have potential applications in quantum information processing. Solid state and cold atom experimental architectures have opened avenues for implementing local Floquet engineering which can achieve spatially modulated quantum control of states. Here, we uncover the novel memory effects of local periodic driving in a nonintegrable spin-half staggered Heisenberg chain. For a boundary-driven protocol at the dynamical freezing frequency, we show the formation of an approximate strong zero mode, a prethermal quasi-local operator, due to the emergence of a discrete global $\mathbb{Z}_2$ symmetry. This is captured by constructing an accurate effective Floquet Hamiltonian using a higher-order partially resummed Floquet-Magnus expansion. The lifetime of the boundary spin can be exponentially enhanced by enlarging the set of suitably chosen driven sites. We demonstrate that in the asymptotic limit, achieved by increasing the number of driven sites, a strong zero mode emerges, where the lifetime of the boundary spin grows exponentially with system size. The non-local processes in the Floquet Hamiltonian play a pivotal role in the total freezing of the boundary spin in the thermodynamic limit. The novel dynamics of the boundary spin is accompanied by a rich structure of entanglement in the Floquet eigenstates where specific bipartitions yield an area-law scaling while the entanglement for random bipartitions scales as a volume-law.
format Preprint
id arxiv_https___arxiv_org_abs_2306_01835
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Emergent strong zero mode through local Floquet engineering
Mukherjee, Bhaskar
Melendrez, Ronald
Szyniszewski, Marcin
Changlani, Hitesh J.
Pal, Arijeet
Strongly Correlated Electrons
Statistical Mechanics
Quantum Physics
Periodically driven quantum systems host exotic phenomena which often do not have any analog in undriven systems. Floquet prethermalization and dynamical freezing of certain observables, via the emergence of conservation laws, are realized by controlling the drive frequency. These dynamical regimes can be leveraged to construct quantum memories and have potential applications in quantum information processing. Solid state and cold atom experimental architectures have opened avenues for implementing local Floquet engineering which can achieve spatially modulated quantum control of states. Here, we uncover the novel memory effects of local periodic driving in a nonintegrable spin-half staggered Heisenberg chain. For a boundary-driven protocol at the dynamical freezing frequency, we show the formation of an approximate strong zero mode, a prethermal quasi-local operator, due to the emergence of a discrete global $\mathbb{Z}_2$ symmetry. This is captured by constructing an accurate effective Floquet Hamiltonian using a higher-order partially resummed Floquet-Magnus expansion. The lifetime of the boundary spin can be exponentially enhanced by enlarging the set of suitably chosen driven sites. We demonstrate that in the asymptotic limit, achieved by increasing the number of driven sites, a strong zero mode emerges, where the lifetime of the boundary spin grows exponentially with system size. The non-local processes in the Floquet Hamiltonian play a pivotal role in the total freezing of the boundary spin in the thermodynamic limit. The novel dynamics of the boundary spin is accompanied by a rich structure of entanglement in the Floquet eigenstates where specific bipartitions yield an area-law scaling while the entanglement for random bipartitions scales as a volume-law.
title Emergent strong zero mode through local Floquet engineering
topic Strongly Correlated Electrons
Statistical Mechanics
Quantum Physics
url https://arxiv.org/abs/2306.01835