Remarks on entanglement and identical particles

Abstract

We argue that in the case of identical particles the most natural identification of separability, that is of absence of non-classical correlations, is via the factorization of mean values of commuting observables. It thus follows that separability and entanglement depend both on the state and on the choice of observables and are not absolute notions. We compare this point of view with a recent novel approach to the entanglement of identical particles, which allows for the definition of an entanglement entropy from a suitably defined reduced particle density matrix, without the need of labeling the system constituents. We contrast this figure of merit with the aforementioned lack of an absolute notion of entanglement by considering few paradigmatic examples.

References in corpus (9)

• Entanglement in fermion systems and quantum metrology
• Squeezing Inequalities and Entanglement for Identical Particles
• Bipartite entanglement in systems of identical particles: the partial transposition criterion
• Entanglement of Identical Particles
• Entanglement of Indistinguishable Particles
• Entanglement robustness and geometry in systems of identical particles
• Quantum teleportation with identical particles
• Universality of Schmidt decomposition and particle identity
• Entanglement and algebraic independence in fermion systems

Cited by in corpus (5)

• Entanglement in indistinguishable particle systems
• Entanglement of indistinguishable particles: a comparative study
• Entanglement of Identical Particles and Coherence in the First Quantization Language
• How squeezed states both maximize and minimize the same notion of quantumness
• Hyper-hybrid entanglement, indistinguishability, and two-particle entanglement swapping