Entanglement of a microcanonical ensemble
Tobias Verhulst, Jan Naudts · Journal of Physics A Mathematical and Theoretical · 2007
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 Jaynes–Cummings 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.