Practical advantage of non-Hermitian enhanced quantum sensing

TL;DR

This paper demonstrates that non-Hermitian quantum sensors can outperform Hermitian ones under realistic noise conditions, offering practical advantages in high-precision sensing despite theoretical limitations.

Contribution

It provides the first comprehensive analysis of non-Hermitian sensors' performance under realistic noise, highlighting their practical benefits over Hermitian systems.

Findings

Non-Hermitian sensors outperform Hermitian ones in noisy environments.

Enhanced susceptibility in non-Hermitian systems amplifies signal response.

Fisher information analysis confirms superior noise resilience.

Abstract

Non-Hermitian systems have emerged as a powerful paradigm for ultrasensitive sensing, leveraging unique spectral and dynamical properties that find no counterparts in Hermitian physics. While recent theoretical assessments have established that these protocols offer no fundamental advantage in the ideal shot-noise-limited regime once the success probability of non-unitary evolution is rigorously accounted for, their practical utility under realistic experimental constraints remains largely unexplored. In this work, we shift the focus toward practical laboratory performance by demonstrating that non-Hermitian sensors can significantly outperform their Hermitian counterparts in the presence of various types of technical noise. This enhancement stems from the significantly enhanced susceptibility, which amplifies the signal response to effectively overcome the floor of technical imperfections. By evaluating the Fisher information under different technical noise models, we further substantiate the superior performance of non-Hermitian sensing. Our results delineate the specific regimes where non-Hermitian platforms yield clear practical gains, offering a concrete avenue for building high-precision, noise-resilient sensors.