Real-time measurement error mitigation for one-way quantum computation

TL;DR

This paper introduces a real-time quantum error mitigation method for measurement errors in one-way quantum computation, using ancilla qubits and voting protocols to improve accuracy during ongoing computations.

Contribution

The paper presents a novel real-time error mitigation scheme for measurement errors in one-way quantum computing, differing from traditional methods that require multiple circuit runs.

Findings

Effective reduction of measurement errors demonstrated in simulations

Analytical expression for error detection probability derived

Method robust against hardware noise and CNOT gate errors

Abstract

We propose a quantum error mitigation scheme for single-qubit measurement errors, particularly suited for one-way quantum computation. Contrary to well established error mitigation methods for circuit-based quantum computation, that require to run the circuits several times, our method is capable of mitigating measurement errors in real-time, during the processing measurements of the one-way computation. For that, an ancillary qubit register is entangled with the to-be-measured qubit and additionally measured afterwards. By using a voting protocol on all measurement outcomes, occurring measurement errors can be mitigated in real-time while the one-way computation continues. We provide an analytical expression for the probability to detect a measurement error in dependency of the error rate and the number of ancilla qubits. From this, we derive an estimate of the ancilla register size for a given measurement error rate and a required success probability to detect a measurement error. Additionally, we also consider the CNOT gate error in our mitigation method and investigate how this influences the probability to detect a measurement error. Finally, we show in proof-of-principle simulations, also considering a hardware noise model, that our method is capable of reducing the measurement errors significantly in a one-way quantum computation with only a small number of ancilla qubits.