Four-Wave Mixing-Induced Maximal Entanglement in Superconducting Phase Quantum Circuits

Abstract

We are interested in studying the entanglement of an array of superconducting phase quantum circuits and external magnetic fluxes. It is shown that in a four-level cascade type quantum system, the degree of entanglement increases by generation of fourth microwave pulse, in multi-photon resonance condition. We achieve the maximal entanglement induced via four-wave mixing in our model. Moreover, it is demonstrated that the population distribution of the dressed states approaches to be uniform as the degree of entanglement becomes maximum. We can control the entanglement of the composite system by changing amplitudes of the applied magnetic fluxes. Our results can be used in quantum information processing via superconducting quantum circuits.