Observation of parametric deamplification in a Josephson parametric amplifier

The successful generation and detection of squeezed electromagnetic radiation at optical frequencies' promise to open the door to the exploration of new quantum phenomena, some of which may be technologically useful. The generation and detection of squeezed radiation at low frequencies would also open the door to the observation of novel quantum phenomena. The authors report here on a Josephson parametric amplifier which appears to be well behaved and may be suitable for generating squeezed coherent microwave radiation. The amplifier was operated in the four-photon or doubly degenerate mode, and thus its operation is akin to that of an optical four-wave mixer