AQP Seminar: Bi-stability in a mesoscopic Josephson junction array resonator and its application

Aalto Quantum Physics Seminar (Nanotalo). Speaker: Phani Raja Muppalla (Institut für Quantenoptik und Quanteninformation, Innsbruck, Austria)

I will present an experimental investigation of stochastic switching of a bistable Josephson junction array resonator with a resonance frequency in the GHz range. As the device is in the regime where the anharmonicity is on the order of the linewidth, the bistability appears for a pump strength of only a few photons. We measure the dynamics of the bistability by continuously observing the jumps between the two metastable states, which occur with a rate ranging from a few Hz down to a few mHz. The switching rate strongly depends on the pump strength, readout strength and the temperature, following Kramers' theory. In the end of my talk, I will talk about the interplay between the nonlinearity and coupling, which provide a new resource of nondemolition measurement for example “A few photon microwave switch”.