LOSS OF COHERENCE OF PURE AND MIXED STATES FOR A MULTIMODE RADIATION FIELD INTERACTING NONLINEARLY WITH A QUBIT

摘要

We study the loss of coherence of pure and mixed states for a nonlinear interaction between the multi-mode field and a qubit. We calculate analytically partial entropies of the qubit and field subsystems, which are used to measure the loss of coherence. We find that the loss of coherence loss is sensitive to the initial field states, the number of modes, and the nonlinear-interaction parameter.