2021/08/04 by Ariel Shlosberg, Shlosberg, Ariel, Anthony Polloreno +4
Computer Science · Physics and Astronomy · #FOS: Physical sciences #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Physics (quant-ph) #Quantum and electron transport phenomena
paper · pdf · doi:10.48550/arxiv.2108.02079
openalex publication_date 2021/08/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Quantum error correction is necessary to perform large-scale quantum\ncomputations in the presence of noise and decoherence. As a result, several\naspects of quantum error correction have already been explored. These have been\nprimarily studies of quantum memory[1, 2], an important first step towards\nquantum computation, where the objective is to increase the lifetime of the\nencoded quantum information. Additionally, several works have explored the\nimplementation of logical gates[3-5]. In this work we study a next step -\nfault-tolerantly implementing quantum circuits. We choose the [[4, 1, 2]]\nBacon-Shor subsystem code, which has a particularly simple error-detection\ncircuit. Through both numerics and site-counting arguments, we compute\npseudo-thresholds for the Pauli error rate p in a depolarizing noise model,\nbelow which the encoded circuits outperform the unencoded circuits. These\npseudo-threshold values are shown to be as high as p=3 % for short circuits,\nand p=0.6 % for circuits of moderate depth. Additionally, we see that\nmultiple rounds of stabilizer measurements give an improvement over performing\na single round at the end. This provides a concrete suggestion for a\nsmall-scale fault-tolerant demonstration of a quantum algorithm that could be\naccessible with existing hardware.\n