Qubit Quasi-Probability Coherence Induced by a Nonlinear Coherent Cavity Filled With a Kerr-Like Medium Under Dissipation Effect.

The work considers a qubit interacting off-resonantly a nonlinear Kerr-like quantum-harmonic-oscillator cavity field through nonlinear intensity-dependent and one-photon interactions. The analytical solution for the master equation is obtained when the qubit starts with an excited pure state while the harmonic-oscillator field starts with a coherent state. The dynamics of the phase space Husimi-distribution and its Wehrl-Husimi entropy entanglement/mixedness is explored under the effects of the atom-field detuning, Kerr-like nonlinearity as well as atomic spontaneous-emission dissipation. For resonant case, the Wehrl-Husimi entropy qubit-oscillator entanglement and atomic mixedness are generated (due to the unitary nonlinear intensity-dependent evolution) with a regular oscillatory behavior. For off-resonant case, the quantum coherence is generated partially with a high-frequency irregular oscillatory behavior. The Kerr-like nonlinearity and the atomic spontaneous dissipation lead to enhancing the generated atomic mixedness Wehrl-Husimi entropy enhances and stabilizing the atomic state in a maximally mixed state. The phase space Husimi-distribution information dynamics of the corresponding the generated atomic mixed states confirms the vital link between the formed interference Husimi-distributions and the generated atomic Wehrl-Husimi entropy mixedness. It is found that the dynamics of the Husimi-distribution information and its Wehrl-Husimi entropy is highly sensitive to the qubit-cavity detuning, Kerr-like nonlinearity as well as the dissipation.