Observation of 4.2K equilibrium noise squeezing via a Josephson parametric amplifier.
01 January 1988
We have demonstrated squeezing of 4.2K thermal noise using a Josephson-parametric amplifier operated at 19.4 GHz. A 42% reduction in the equilibrium noise was observed. The amplifier has been operated at 0.1K with an excess noise of 0.28K referred to the amplifier's input port. This is less than but comparable to the contribution of vacuum fluctuation noise H nu/2K = 0. 47K at 19.4 GHz.