Effects of a phase-damping cavity on entanglement and purity loss in two-qubit system

We analyze two identical qubits interacting with a single-mode quantized radiation field, taking into account the influence of phase damping. The qubits are assumed to be initially in a superposition of the excited and the ground states, and the field is in a coherent state. The effects of the damping on the purity loss of the system and different bipartite partitions of the system [field-two qubits, qubit–(field + qubit)] through the tangles are considered. The effect of the damping on the entanglement of field qubits state is evaluated by the negativity. It is noted that the phenomenon of death and rebirth of the entanglement appears. With the increase in the phase parameter, this phenomenon disappears.