Ensemble averaged entanglement of identical particles

ua nt - p h / 07 03 24 3 v 2 3 A pr 2 00 7 Ensemble averaged entanglement of two - particle states in Fock space

Recent results, extending the Schmidt decomposition theorem to wavefunctions of pairs 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 ...

Entanglement of a microcanonical ensemble

We replace time-averaged entanglement by ensemble-averaged entanglement and derive a simple expression for the latter. We show how to calculate the ensemble average for a two-spin system and for the JaynesCummings model. In both cases the time-dependent entanglement is known as well so that one can verify that the time average coincides with the ensemble average.

Entanglement and extreme spin squeezing.

For any mean value of a Cartesian component of a spin vector we identify the smallest possible uncertainty in any of the orthogonal components. The corresponding states are optimal for spectroscopy and atomic clocks. We show that the results for different spin J can be used to identify entanglement and to quantify the depth of entanglement in systems with many particles. With the procedure deve...

Entanglement of Identical Particles

Entanglement of Identical Particles and Reference Phase Uncertainty