Many-particle entanglement criterion for superradiant-like states

TL;DR

This paper introduces a new criterion for detecting many-particle entanglement in superradiant-like states, effective near Dicke states and during superradiance evolution, with implications for understanding collective quantum phenomena.

Contribution

It presents a novel inseparability criterion linking single-mode and many-particle nonclassicalities, applicable to mixed states and superradiant states, advancing entanglement detection methods.

Findings

Effective in identifying entanglement near Dicke states

Works well for superradiant ground states and dynamics

Reveals wave function bunching despite sub-Poissonian excitations

Abstract

We derive a many-particle inseparability criterion for mixed states using the relation between single-mode and many-particle nonclassicalities. It works very well not only in the vicinity of the Dicke states, but also for the superposition of them: superradiant ground state of finite/infinite number of particles and time evolution of single-photon superradiance. We also obtain a criterion for ensemble-field entanglement which works fine for such kind of states. Even though the collective excitations of the many-particle system is sub-Poissonian --which results in entanglement-- the wave function displays bunching.