Multiensemble Superradiance for Distributed Quantum Sensing

TL;DR

This paper introduces multiensemble superradiance, extending Dicke superradiance to multiple ensembles, and demonstrates how dark states and entanglement can be exploited for enhanced distributed quantum sensing.

Contribution

It derives analytical covariance matrices for dark states in multiensemble superradiance, linking metrological sensitivity to the geometric structure of the dynamics and proposing an optimal sensing protocol.

Findings

Analytical covariance matrices for dark states in large-N limit.

Inter-ensemble entanglement enhances quantum metrology.

Optimal multiparameter estimation protocol demonstrated.

Abstract

Multiensemble superradiance extends Dicke superradiance to multiple ensembles and supports dark states whose properties depend on the initial state. In the large-\(N\) limit, we derive analytical covariance matrices for these dark states, revealing inter-ensemble entanglement that enhances quantum metrology. The minimum eigenvalue, determined by the curvature of the superradiance potential, corresponds to the optimal multiparameter spin-squeezing coefficient, which is given by the \emph{Rayleigh quotient} of the spin-squeezing matrix, linking metrological sensitivity to the geometric structure of the underlying dynamics. The multiparameter squeezing coefficient provides a variational framework for optimizing metrological performance. These results enable optimal estimation of arbitrary linear combinations of multiple parameters, offering a concrete protocol for distributed quantum sensing and a promising route toward multimode quantum interferometry.