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Bibliographic Details
Main Authors: Kunjummen, Jonathan, Taylor, Jacob M.
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2511.01080
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author Kunjummen, Jonathan
Taylor, Jacob M.
author_facet Kunjummen, Jonathan
Taylor, Jacob M.
contents Quantum error correction uses the measurement of syndromes and classical decoding algorithms to estimate the location and type of errors while protecting the encoded quantum bits. Here we consider how prior information and Bayesian updates can play a critical role in improving the performance of QEC in the scenario of a particularly noisy qubit. This allows for leveraging even distance codes, which typically are less valued in QEC, to handle the noisy qubit, changing the power-law scaling of the logical error rate with the baseline physical error rate. A crucial component of this is updating the prior by real time feeding of decoder outputs into a approximate Kalman filter. Thus our approach provides a bootstrap to the actual error rates. We show this via simulation of the full closed-loop system: starting from uniform priors, the update procedure gradually learns site-specific error rates, enabling the decoder to outperform a fixed-prior baseline. In turn, we show that this enables in situ calibration of unitary operations via injection of gate set tomography operations with only moderate overhead in the more typical scenario of low noise qubits.
format Preprint
id arxiv_https___arxiv_org_abs_2511_01080
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle In situ calibration of unitary operations during quantum error correction
Kunjummen, Jonathan
Taylor, Jacob M.
Quantum Physics
Quantum error correction uses the measurement of syndromes and classical decoding algorithms to estimate the location and type of errors while protecting the encoded quantum bits. Here we consider how prior information and Bayesian updates can play a critical role in improving the performance of QEC in the scenario of a particularly noisy qubit. This allows for leveraging even distance codes, which typically are less valued in QEC, to handle the noisy qubit, changing the power-law scaling of the logical error rate with the baseline physical error rate. A crucial component of this is updating the prior by real time feeding of decoder outputs into a approximate Kalman filter. Thus our approach provides a bootstrap to the actual error rates. We show this via simulation of the full closed-loop system: starting from uniform priors, the update procedure gradually learns site-specific error rates, enabling the decoder to outperform a fixed-prior baseline. In turn, we show that this enables in situ calibration of unitary operations via injection of gate set tomography operations with only moderate overhead in the more typical scenario of low noise qubits.
title In situ calibration of unitary operations during quantum error correction
topic Quantum Physics
url https://arxiv.org/abs/2511.01080