Control-enhanced quantum metrology under Markovian noise

TL;DR

This paper introduces a control-enhanced quantum metrology method that adapts encoding dynamics to mitigate Markovian noise, significantly improving parameter estimation precision in realistic noisy environments.

Contribution

It proposes a novel control-based scheme that automatically optimizes quantum states against noise, outperforming standard and ancilla-assisted methods in frequency estimation tasks.

Findings

Achieves up to tenfold improvement in estimation precision

Demonstrates effectiveness through numerical simulations

Validates scheme with a nuclear magnetic resonance experiment

Abstract

Quantum metrology is supposed to significantly improve the precision of parameter estimation by utilizing suitable quantum resources. However, the predicted precision can be severely distorted by realistic noises. Here, we propose a control-enhanced quantum metrology scheme to defend against these noises for improving the metrology performance. Our scheme can automatically alter the parameter encoding dynamics with adjustable controls, thus leading to optimal resultant states that are less sensitive to the noises under consideration. As a demonstration, we numerically apply it to the problem of frequency estimation under several typical Markovian noise channels. Through comparing our control-enhanced scheme with the standard scheme and the ancilla-assisted scheme, we show that our scheme performs better and can improve the estimation precision up to around one order of magnitude. Furthermore, we conduct a proof-of-principle experiment in nuclear magnetic resonance system to verify the effectiveness of the proposed scheme. The research here is helpful for current quantum platforms to harness the power of quantum metrology in realistic noise environments.