Entanglement Sustainability in Quantum Radar

Abstract

Quantum radar is generally defined as a detection sensor that utilizes the microwave photons like a classical radar. At the same time, it employs quantum phenomena to improve detection, identification, and resolution capabilities. However, the entanglement is so fragile, unstable, and difficult to create and to preserve for a long time. Also, more importantly, the entangled states have a tendency to leak away as a result of noise. The points mentioned above enforces that the entangled states should be carefully studied at each step of the quantum radar detection processes as follows. Firstly, the creation of the entanglement between microwave and optical photons into the tripartite system is realized. Secondly, the entangled microwave photons are intensified. Thirdly, the intensified photons are propagated into the atmosphere (attenuation medium) and reflected from a target. Finally, the backscattered photons are intensified before the detection. At each step, the parameters related to the real mediums and target material can affect the entangled states to leak away easily. In this article, the entanglement behavior of a designed quantum radar is specifically investigated. In this study, the quantum electrodynamics theory is generally utilized to analyze the quantum radar system to define the parameters influencing the entanglement behavior. The tripartite system dynamics of equations of motions are derived using the quantum canonical conjugate method. The results of simulations indicate that the features of the tripartite system and the amplifier are designed in such a way to lead the detected photons to remain entangled with the optical modes.