Relationship between the linear entropy, the von Neumann entropy and the atomic Wehrl entropy for the Jaynes-Cummings model

摘要

The linear entropy, the von Neumann entropy and the atomic Wehrl entropy arefrequently used to quantify entanglement in the quantum systems. Theserelations provide typical information on the entanglement in theJaynes-Cummings model (JCM). In this Letter, we explain the origin of thisanalytically and derive a closed form for the atomic Wehrl entropy. Moreover,we show that it is more convenient to use the Bloch sphere radius forquantifying entanglement in the JCM instead of these entropic relations.