Robustness against pump noise of 3-wave mixing Josephson parametric amplifiers

Josephson Parametric Amplifiers (JPAs) are a key component in superconducting quantum information processing. Traditionally, the cable delivering rf pump to a JPA are attenuated heavily at cryogenic stages for thermalization, as all the input lines inside a dilution refrigerator. It is possible however, to afford less attenuation on the pump line without harming the noise performance of a 3-wave mixing JPA, whose pump is spectrally distant from the signal. In this talk, we discuss how does input noise in signal band and pump band affects JPA performance separately. We show experimentally that a resonant 3-wave mixing JPA based on SNAILs can provide near quantum-limited signal amplification under pump band noise temperature of more than several hundred Kelvin.