Enhancing quantum illumination effects using Kerr and Cross-Kerr media in electro-opto-mechanical transducer

Recently in [Phys. Rev. Lett. 114, 080503 (2015)] an electro-opto-mechanical converter has been used to evaluate microwave-optical entanglement, applicable in the quantum illumination techniques at microwave frequencies. Choosing this frequency domain is due to the fact that, microwaves have generally a more suitable spectral region for target detection than light waves. In this paper we aim to investigate the effect of nonlinear Kerr and cross-Kerr media on the microwave-optical entanglement degree in an electro-opto-mechanical transducer. We evaluate some key measures of the system, i.e., entanglement metrics, logarithmic negativity, coherent information and quantum discord. Our analysis demonstrates that, adding Kerr and cross-Kerr terms to the Hamiltonian of the electro-opto-mechanical system increases the entanglement metric, logarithmic negativity and quantum discord by approximately 3 to 4 times and the coherent information increases slightly, whenever the system possesses strong opticalmechanical coupling, low optical dissipation or both conditions. Conversely, when the system possesses weak optical-mechanical coupling, high optical dissipation or both conditions, it leads to weakening/death of all above-considered criteria. The constructive effect of Kerr media on the above quantumness signs makes the system more beneficial for quantum illumination purposes, which is an important factor in the quantum information science and technologies.