Entanglement and squeezing in solid-state circuits

We investigate the dynamics of a system consisting of a Cooper-pair box and two superconducting transmission line resonators. There exist both linear and nonlinear interactions in such a system. We show that a single-photon entanglement state can be generated in a simple way in the linear interaction regime. In the nonlinear interaction regime, we propose a scheme for generating squeezed states of microwaves using three-wave mixing in solid-state circuits.