Fault-Tolerant Belief Propagation for Practical Quantum Memory

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Kuo, Kao-Yueh, Lai, Ching-Yi
Natura: Preprint
Pubblicazione: 2024
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866913521202102272
author Kuo, Kao-Yueh
Lai, Ching-Yi
author_facet Kuo, Kao-Yueh
Lai, Ching-Yi
contents A fault-tolerant approach to reliable quantum memory is essential for scalable quantum computing, as physical qubits are susceptible to noise. Quantum error correction (QEC) must be continuously performed to prolong the memory lifetime. In QEC, error syndromes are generated rapidly, often within the execution time of a few quantum gates, requiring decoders to process this error data with equal speed. A typical QEC cycle involves multiple rounds of syndrome measurements, causing potential error locations to scale rapidly with the code size and the number of measurement rounds. However, no such decoders currently exist for general quantum low-density parity-check codes. In this paper, we propose a fault-tolerant belief propagation (FTBP) decoder that utilizes a space-time Tanner graph across multiple rounds of syndrome extraction with mixed-alphabet error variables. To enhance FTBP, we introduce a technique of probabilistic error consolidation to mitigate degeneracy effects and short cycles. Additionally, we propose an adaptive sliding window procedure that captures long error events across window boundaries and adjusts the decoding in real time. Our simulations demonstrate high error thresholds of 0.4%-0.87% and strong error-floor performance for topological code families, including rotated toric, toric color, and twisted XZZX toric codes.
format Preprint
id arxiv_https___arxiv_org_abs_2409_18689
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Fault-Tolerant Belief Propagation for Practical Quantum Memory
Kuo, Kao-Yueh
Lai, Ching-Yi
Quantum Physics
A fault-tolerant approach to reliable quantum memory is essential for scalable quantum computing, as physical qubits are susceptible to noise. Quantum error correction (QEC) must be continuously performed to prolong the memory lifetime. In QEC, error syndromes are generated rapidly, often within the execution time of a few quantum gates, requiring decoders to process this error data with equal speed. A typical QEC cycle involves multiple rounds of syndrome measurements, causing potential error locations to scale rapidly with the code size and the number of measurement rounds. However, no such decoders currently exist for general quantum low-density parity-check codes. In this paper, we propose a fault-tolerant belief propagation (FTBP) decoder that utilizes a space-time Tanner graph across multiple rounds of syndrome extraction with mixed-alphabet error variables. To enhance FTBP, we introduce a technique of probabilistic error consolidation to mitigate degeneracy effects and short cycles. Additionally, we propose an adaptive sliding window procedure that captures long error events across window boundaries and adjusts the decoding in real time. Our simulations demonstrate high error thresholds of 0.4%-0.87% and strong error-floor performance for topological code families, including rotated toric, toric color, and twisted XZZX toric codes.
title Fault-Tolerant Belief Propagation for Practical Quantum Memory
topic Quantum Physics
url https://arxiv.org/abs/2409.18689