Quantum metrology with one auxiliary particle in a correlated bath and its quantum simulation

TL;DR

This paper introduces a measurement scheme using a single auxiliary qubit to counteract environmental noise in quantum metrology, achieving near-Heisenberg limit precision and verified through quantum simulation.

Contribution

It proposes a novel auxiliary-qubit-based measurement scheme that enhances precision in correlated environments, outperforming existing methods with fewer resources.

Findings

Approaches the Heisenberg limit in estimation precision.

Outperforms other proposals in resource efficiency.

Effective in various correlated environment models.

Abstract

In realistic metrology, entangled probes are more sensitive to noise, especially for a correlated environment. The precision of parameter estimation with entangled probes is even lower than that of the unentangled ones in a correlated environment. In this paper, we propose a measurement scheme with only one auxiliary qubit, which can selectively offset the impact of environmental noise under this situation. We analyse the estimation precision of our scheme and find out that it approaches the Heisenberg limit when prepared in a proper auxiliary state. We further discuss employing auxiliary states to improve the precision of measurement in other environment models such as a partially-correlated environment. In order to verify our scheme, we apply a recently-developed quantum algorithm to simulate the quantum dynamics of our proposal and show that it outperform the other proposals with less resources.