Dissipative superradiant spin amplifier for enhanced quantum sensing

TL;DR

This paper introduces a dissipative superradiant spin amplification protocol that significantly enhances quantum sensing sensitivity by leveraging collective spin decay, even amid dissipation and noise, applicable to solid-state spin ensembles.

Contribution

The authors propose a novel dissipative protocol utilizing superradiant decay to improve quantum sensing sensitivity without altering existing readout mechanisms.

Findings

Approaches SQL-like scaling in N despite dissipation.

Compatible with solid-state spin ensemble platforms.

Enhances measurement sensitivity in noisy environments.

Abstract

Quantum metrology protocols exploiting ensembles of $N$ two-level systems and Ramsey-style measurements are ubiquitous. However, in many cases excess readout noise severely degrades the measurement sensitivity; in particular in sensors based on ensembles of solid-state defect spins. We present a dissipative "spin amplification" protocol that allows one to dramatically improve the sensitivity of such schemes, even in the presence of realistic intrinsic dissipation and noise. Our method is based on exploiting collective (i.e., superradiant) spin decay, an effect that is usually seen as a nuisance because it limits spin-squeezing protocols. We show that our approach can allow a system with a highly imperfect spin readout to approach SQL-like scaling in $N$ within a factor of two, without needing to change the actual readout mechanism. Our ideas are compatible with several state-of-the-art experimental platforms where an ensemble of solid-state spins (NV centers, SiV centers) is coupled to a common microwave or mechanical mode.