Identical Quantum Particles, Entanglement, and Individuality

Entanglement of Identical Particles

Quantum entanglement of identical particles by standard information-theoretic notions

Quantum entanglement of identical particles is essential in quantum information theory. Yet, its correct determination remains an open issue hindering the general understanding and exploitation of many-particle systems. Operator-based methods have been developed that attempt to overcome the issue. Here we introduce a state-based method which, as second quantization, does not label identical par...

Ensemble averaged entanglement of identical particles

Recent results, extending the Schmidt decomposition theorem to wavefunctions of identical particles, are reviewed. They are used to give a definition of reduced density operators in the case of two identical particles. Next, a method is discussed to calculate time averaged entanglement. It is applied to a pair of identical electrons in an otherwise empty band of the Hubbard model, and to a pair...

Identical Quantum Particles and Weak

We examine a recent argument that " identical " quantum particles with an anti-symmetric state (fermions) are weakly discernible objects, just like irreflexively related ordinary objects in situations with perfect symmetry (Black's spheres, for example). We conclude that the argument uses a silent premise that is not justified in the quantum case. 1 Individuality Objects are individuals. One mi...

Identical Particles and Quantum Symmetries

We propose a solution to the problem of compatibility of Bose-Fermi statistics with symmetry transformations implemented by compact quantum groups of Drinfel’d type. We use unitary transformations to conjugate multiparticle symmetry postulates, so as to obtain a twisted realization of the symmetric groups Sn. *A. v. Humboldt-fellow e-mail: Fiore, Schupp @ ls-wess.physik.uni-muenchen.de