Entanglement-Enhanced Quantum Metrology in Colored Noise by Quantum Zeno Effect

TL;DR

This paper experimentally verifies that entangled probes, combined with the quantum Zeno effect, can enhance quantum metrology precision in non-Markovian noisy environments, achieving a measurable improvement with up to seven qubits.

Contribution

It demonstrates experimentally that entangled probes improve quantum metrology precision via the quantum Zeno effect in non-Markovian noise, confirming theoretical predictions.

Findings

Precision improved by a factor of n^{1/4} with up to 7 qubits

Entangled probes outperform unentangled in non-Markovian noise

Quantum simulation approach effectively verifies quantum metrology schemes

Abstract

In open quantum systems, the precision of metrology inevitably suffers from the noise. {In Markovian open quantum dynamics, the precision can not be improved by using entangled probes although the measurement time is effectively shortened.} However, it was predicted over one decade ago that in a non-Markovian one, the error can be significantly reduced by the quantum Zeno effect (QZE) [Chin, Huelga, and Plenio, Phys. Rev. Lett. \textbf{109}, 233601 (2012)]. In this work, we apply a recently-developed quantum simulation approach to experimentally verify that entangled probes can improve the precision of metrology by the QZE. Up to $n=7$ qubits, we demonstrate that the precision has been improved by a factor of $n^{1/4}$, which is consistent with the theoretical prediction. Our quantum simulation approach may provide an intriguing platform for experimental verification of various quantum metrology schemes.