Mitigating depolarizing noise on quantum computers with noise-estimation circuits

TL;DR

This paper introduces a method to mitigate depolarizing noise in quantum computers by estimating its rate with specialized circuits and applying corrections, significantly improving accuracy in large quantum circuits.

Contribution

The paper presents a novel noise mitigation technique using noise-estimation circuits to correct depolarizing noise in quantum computations.

Findings

Effective noise mitigation in large quantum circuits

Close approximation to exact results with combined error correction methods

Validated approach on Heisenberg model simulations

Abstract

A significant problem for current quantum computers is noise. While there are many distinct noise channels, the depolarizing noise model often appropriately describes average noise for large circuits involving many qubits and gates. We present a method to mitigate the depolarizing noise by first estimating its rate with a noise-estimation circuit and then correcting the output of the target circuit using the estimated rate. The method is experimentally validated on the simulation of the Heisenberg model. We find that our approach in combination with readout-error correction, randomized compiling, and zero-noise extrapolation produces results close to exact results even for circuits containing hundreds of CNOT gates.