Bounded light cone and robust topological order out of equilibrium

Fuente: arXiv
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Main Authors: Zeng, Yu, Hamma, Alioscia, Zhang, Yu-Ran, Cao, Jun-Peng, Fan, Heng, Liu, Wu-Ming
Format: Preprint
Published: 2022
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author Zeng, Yu
Hamma, Alioscia
Zhang, Yu-Ran
Cao, Jun-Peng
Fan, Heng
Liu, Wu-Ming
author_facet Zeng, Yu
Hamma, Alioscia
Zhang, Yu-Ran
Cao, Jun-Peng
Fan, Heng
Liu, Wu-Ming
contents The ground state degeneracy of topologically ordered gapped Hamiltonians is the bedrock for self-correcting quantum memories, which are unfortunately not stable away from equilibrium even at zero temperature. This plague precludes practical robust self-correction since stability at zero temperature is a prerequisite for finite-temperature robustness. In this work, we show that the emergence of a bounded light cone renders the unitary time evolution a quasi-adiabatic continuation that preserves topological order, with the initial ground space retaining its macroscopic distance at all times as a quantum code. We also show how bounded light cones can emerge through suitable perturbations in Kitaev's toric code and honeycomb model. Our results suggest that topological orders and self-correcting quantum memories can be dynamically robust at zero temperature.
format Preprint
id arxiv_https___arxiv_org_abs_2208_13839
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Bounded light cone and robust topological order out of equilibrium
Zeng, Yu
Hamma, Alioscia
Zhang, Yu-Ran
Cao, Jun-Peng
Fan, Heng
Liu, Wu-Ming
Quantum Physics
The ground state degeneracy of topologically ordered gapped Hamiltonians is the bedrock for self-correcting quantum memories, which are unfortunately not stable away from equilibrium even at zero temperature. This plague precludes practical robust self-correction since stability at zero temperature is a prerequisite for finite-temperature robustness. In this work, we show that the emergence of a bounded light cone renders the unitary time evolution a quasi-adiabatic continuation that preserves topological order, with the initial ground space retaining its macroscopic distance at all times as a quantum code. We also show how bounded light cones can emerge through suitable perturbations in Kitaev's toric code and honeycomb model. Our results suggest that topological orders and self-correcting quantum memories can be dynamically robust at zero temperature.
title Bounded light cone and robust topological order out of equilibrium
topic Quantum Physics
url https://arxiv.org/abs/2208.13839