2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/125342In this paper, by using the notion of negativity, we study the degree of entanglement of a two-level atom interacting with a quantized radiation field, described by the Jaynes-Cummings model (JCM). We suppose that initially the field is in a pure state and the atom is in a general mixed state. In this case the negativity fully captures the entanglement of the JCM. We investigate the case for that the initial state of the field is a coherent state. The influences of the detuning on the degree of entanglement is also examined.10 pages, 5 figuresQuantum Physicstext