Photon statistics of a Josephson parametric amplifier from continuous microwave measurements*

The electric ac current flowing though a mesoscopic device exhibits rich electromagnetic fluctuations.[1] Those fluctuations can either be studied through the lens of charge transport or that of quantum optics. In the quantum optics perspective, it is possible to measure the discrete photon statistics of a microwave signal using the cumulants of its continuous voltage fluctuations.[2] I will present recent results for the photon statistics of a Josephson parametric amplifier, the archetypal source of squeezed states in the microwave domain. The results convincingly agree with an input-ouput model of the device and measurement setup.

[1] Rolf Landauer. Nature 392, 658-659 (1998)
[2] Virally et al. PRA 93, 043813 (2016)