Spectral Transfer Tensor Method for Non-Markovian Noise Characterization

TL;DR

This paper introduces Spectral Transfer Tensor Maps (SpecTTM), an experimental protocol that accurately characterizes non-Markovian noise in quantum channels, including reconstructing noise spectra for Pauli channels without SPAM errors.

Contribution

The paper presents a novel protocol, SpecTTM, for precise non-Markovian noise characterization and spectrum reconstruction in quantum channels, especially for Pauli channels, without requiring state-preparation and measurement errors.

Findings

SpecTTM accurately predicts RHP non-Markovian measure for Pauli channels.

It enables high-precision noise spectrum reconstruction for qubits.

The method can be extended to non-Pauli channels via Pauli twirling.

Abstract

With continuing improvements on the quality of fabricated quantum devices, it becomes increasingly crucial to analyze noisy quantum process in greater details such as characterizing the non-Markovianity in a quantitative manner. In this work, we propose an experimental protocol, termed Spectral Transfer Tensor Maps (SpecTTM), to accurately predict the RHP non-Markovian measure of any Pauli channels without state-preparation and measurement (SPAM) errors. In fact, for Pauli channels, SpecTTM even allows the reconstruction of highly-precised noise power spectrum for qubits. At last, we also discuss how SpecTTM can be useful to approximately characterize non-Markovianity of non-Pauli channels via Pauli twirling in an optimal basis.