Tripartite entanglement of microwave radiation via nonlinear parametric interactions enhanced by quantum interference in superconducting quantum circuits

Abstract

We present an efficient scheme for generating the tripartite continuous variable entanglement of microwave radiation in a Δ-type three-level artificial atom placed in a transmission line resonator, simultaneously driven resonantly by two strong electromagnetic fields. We show that it is possible to obtain the full tripartite entanglement with the different frequencies in the presence of atom and cavity decays. In our scheme, interestingly, the nonlinear process of simultaneous parametric downconversion and upconversion interactions between microwave modes can be achieved via quantum interference induced by two classical fields and can be greatly enhanced under the condition of resonant driving of the two classical fields. Such a nonlinear interaction is responsible for the generation of the strong tripartite entanglement among three microwave modes. In practice, the system considered here could offer an alternative for implementing the scalable information processing in the solid-state system.