Squeezing microwave photon using a Josephson parametric amplifier

Abstract

The squeezed state is important to detect a weak signal with a low noise level and apply to the quantum entanglement. Josephson parametric amplifier (JPA) is a representative nonlinear resonator that can be used to generate the squeezed state in microwave frequencies. We fabricated the JPA consisting of LC resonator terminated with SQUID. The squeezed state is produced when the JPA operates in the degenerate mode, in which the pump frequency is twice the signal frequency. Here, we used the homodyne detection technique to characterize the generated squeezed state. Finally, we performed the tomographical reconstruction of the squeezed state by using the Wigner function.