Entanglement in Coupled Mesoscopic Circuits

A common two-mode squeezed state is one of the most important resources in quantum information processing of continuous variables. In this paper, a two-mode squeezed rotation-entangled state is obtained in coupled mesoscopic circuits. It is shown that instantaneously switching on the external sources may result in a two-mode squeezed state of the system, which actually arises from the coupling effect. The entanglement of the squeezed rotation-entangled state is studied. The degree of entanglement for coupled mesoscoipc circuit was calculated by using the technique of integration within an ordered product of operators. It is shown that the entanglement of the two-mode squeezed rotation-entangled state is different from that of the common squeezed state, for example, the degree of entanglement of the system, which is in the squeezed state, exist maximum value at a very low temperature.