Bounds on Autonomous Quantum Error Correction

Fuente: arXiv
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Main Authors: Shtanko, Oles, Liu, Yu-Jie, Lieu, Simon, Gorshkov, Alexey V., Albert, Victor V.
Format: Preprint
Published: 2023
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author Shtanko, Oles
Liu, Yu-Jie
Lieu, Simon
Gorshkov, Alexey V.
Albert, Victor V.
author_facet Shtanko, Oles
Liu, Yu-Jie
Lieu, Simon
Gorshkov, Alexey V.
Albert, Victor V.
contents Autonomous quantum memories are a way to passively protect quantum information using engineered dissipation that creates an ``always-on'' decoder. We analyze Markovian autonomous decoders that can be implemented with a wide range of qubit and bosonic error-correcting codes, and derive several upper bounds and a lower bound on the logical error rate in terms of correction and noise rates. These bounds suggest that, in general, there is always a correction rate, possibly size-dependent, above which autonomous memories exhibit arbitrarily long coherence times. For any given autonomous memory, size dependence of this correction rate is difficult to rule out: we point to common scenarios where autonomous decoders that stochastically implement active error correction must operate at rates that grow with code size. For codes with a threshold, we show that it is possible to achieve faster-than-polynomial decay of the logical error rate with code size by using superlogarithmic scaling of the correction rate. We illustrate our results with several examples. One example is an exactly solvable global dissipative toric code model that can achieve an effective logical error rate that decreases exponentially with the linear lattice size, provided that the recovery rate grows proportionally with the linear lattice size.
format Preprint
id arxiv_https___arxiv_org_abs_2308_16233
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Bounds on Autonomous Quantum Error Correction
Shtanko, Oles
Liu, Yu-Jie
Lieu, Simon
Gorshkov, Alexey V.
Albert, Victor V.
Quantum Physics
Autonomous quantum memories are a way to passively protect quantum information using engineered dissipation that creates an ``always-on'' decoder. We analyze Markovian autonomous decoders that can be implemented with a wide range of qubit and bosonic error-correcting codes, and derive several upper bounds and a lower bound on the logical error rate in terms of correction and noise rates. These bounds suggest that, in general, there is always a correction rate, possibly size-dependent, above which autonomous memories exhibit arbitrarily long coherence times. For any given autonomous memory, size dependence of this correction rate is difficult to rule out: we point to common scenarios where autonomous decoders that stochastically implement active error correction must operate at rates that grow with code size. For codes with a threshold, we show that it is possible to achieve faster-than-polynomial decay of the logical error rate with code size by using superlogarithmic scaling of the correction rate. We illustrate our results with several examples. One example is an exactly solvable global dissipative toric code model that can achieve an effective logical error rate that decreases exponentially with the linear lattice size, provided that the recovery rate grows proportionally with the linear lattice size.
title Bounds on Autonomous Quantum Error Correction
topic Quantum Physics
url https://arxiv.org/abs/2308.16233