WITNESSING PAIRING CORRELATIONS IN IDENTICAL-PARTICLE SYSTEMS

Quantum correlations and entanglement in identical-particle systems have been a puzzling question which has attracted vast interest and widely different approaches. Witness formalism developed first for entanglement measurement can be adopted to other kind of correlations. An approach is introduced by Kraus et al., [Phys. Rev. A 79, 012306 (2009)] based on pairing correlations in fermionic systems and the use of witness formalism to detect pairing. In this contribution, a two-particle-annihilation operator is used for constructing a two-particle observable as a candidate witness for pairing correlations of both fermionic and bosonic systems. The corresponding separability bounds are also obtained. Two different types of separability definition are introduced for bosonic systems and the separability bounds associated with each type are discussed.

Automated summary

The discussion in the passage mainly focuses on quantum correlations and entanglement in identical-particle systems, introducing an approach based on witness formalism to detect pairing relationships, and discussing separability bounds and their different definitions' impact on bosonic systems.