PT-symmetric quantum sensing: advantages and restrictions

TL;DR

This paper investigates PT-symmetric quantum sensing, revealing that advantages over traditional methods depend on extra information resources and are limited by resource consumption, impacting practical quantum precision measurement.

Contribution

It provides a theoretical analysis of PT-symmetric quantum sensing, highlighting conditions for advantages and practical restrictions, based on experimental schemes with trapped ions.

Findings

Advantages depend on additional information resources.

Resource consumption limits practical applications.

PT-symmetric sensing can outperform Hermitian systems under certain conditions.

Abstract

Quantum sensing utilizing unique quantum properties of non-Hermitian systems to realize ultra-precision measurements has been attracting increasing attention. However, the debate on whether non-Hermitian systems are superior to Hermitian counterparts in sensing remains an open question. Here, we investigate the quantum information in PT-symmetric quantum sensing utilizing two experimental schemes based on the trapped-ion platform. It turns out that the existence of advantages of non-Hermitian quantum sensing heavily depends on additional information resources carried by the extra degrees of freedom introduced to construct PT-symmetric quantum sensors. Moreover, the practical application of non-Hermitian quantum sensing with superior performance is primarily restricted by the additional resource consumption accompanied by the post-selection. Our study provides theoretical references for the construction of non-Hermitian quantum sensors with superior performance and has potential applications in research fields of quantum precision measurement and quantum information processing.