Entanglement of Indistinguishable Particles

TL;DR

This paper introduces a general criterion for entanglement in systems of N indistinguishable particles divided into arbitrary subsystems, based on measurable correlations, unifying previous approaches and identifying universally separable states.

Contribution

It provides a unified framework for entanglement of indistinguishable particles and characterizes a class of bosonic states that are universally separable.

Findings

i.i.d. states are universally separable

Unified criterion for entanglement in indistinguishable particles

Addresses the s=2 case and generalizes to arbitrary subsystems

Abstract

We present a general criterion for entanglement of N indistinguishable particles decomposed into arbitrary s subsystems based on the unambiguous measurability of correlation. Our argument provides a unified viewpoint on the entanglement of indistinguishable particles, which is still unsettled despite various proposals made mainly for the s = 2 case. Even though entanglement is defined only with reference to the measurement setup, we find that the so-called i.i.d. states form a special class of bosonic states which are universally separable.