Real-time adaptation of quantum noise channel estimates

TL;DR

This paper introduces a real-time method for adapting quantum noise channel estimates during quantum circuit execution, utilizing flag gadgets, measurements, and Bayesian inference to improve error mitigation and correction.

Contribution

It presents a novel protocol for real-time calibration of quantum gate error estimates, addressing device drift and fluctuations during quantum computations.

Findings

Demonstrates effectiveness through analytical calculations.

Validates approach with numerical simulations.

Shows potential for improved error mitigation in quantum computing.

Abstract

Estimates of noise channels for quantum gates are required for most error mitigation techniques and are desirable for informing quantum error correction decoders. These estimates can be obtained by resource-intensive off-line characterization techniques, but can become stale due to device drift and fluctuations. We propose a method to address this issue by performing real-time adaptation of noise channel estimates during the execution of a quantum algorithmic circuit using extended flag gadgets, mid-circuit measurements and Bayesian inference. We carry out analytical calculations and numerical simulations employing a Dirichlet prior distribution for the error rates in a Pauli channel to demonstrate and evaluate the technique, which can be seen as a protocol for real-time calibration of high-level gate error information.