A short note on effective Pauli noise models

TL;DR

This paper presents a straightforward method to derive an effective Pauli noise model from classical simulations of noisy quantum gates, aiding in understanding and approximating quantum errors.

Contribution

It introduces a simple prescription to extract the closest Pauli channel approximation to a given quantum error channel based on Frobenius distance.

Findings

Provides a practical method for noise modeling in quantum gates

Highlights issues with the quantitative treatment of coherent errors

Offers insights into approximating complex quantum errors with simpler models

Abstract

We provide a simple prescription to extract an effective Pauli noise model from classical simulations of a noisy experimental protocol for a unitary gate. This prescription yields the closest Pauli channel approximation to the error channel associated with the gate implementation, as measured by the Frobenius distance between quantum channels. Informed by these results, we highlight some puzzles regarding the quantitative treatment of coherent errors.