Properties of field quantum entropy evolution in the Jaynes--Cummings model with initial squeezed coherent states field

The properties of the field quantum entropy evolution in a system ofa single-mode squeezed coherent state field interacting with atwo-level atom is studied by utilizing the complete quantum theory,and we focus our attention on the discussion of the influences offield squeezing parameter $gamma $, atomic distribution angle$theta $ and coupling strength $g$ between the field and the atomon the properties of the evolution of field quantum entropy. Theresults obtained from numerical calculation indicate that theamplitude of oscillation of field quantum entropy evolutiondecreases with the increasing of squeezing parameter $gamma $, andthat both atomic distribution angle $theta $ and coupling strength$g$ between the field and the atom can influence the periodicity offield quantum entropy evolution.