Selected Publications

Bifurcation, mode coupling and noise in a nonlinear multimode superconducting microwave resonator

Tancredi, G., Ithier, G. and Meeson, P.

The addition of nonlinearity to an harmonic resonator provides a route to complex dynamical behaviour of resonant modes, including coupling between them. We present a superconducting device that makes use of the nonlinearity of Josephson junctions to introduce a controlled, tunable, nonlinear inductance to a thin film coplanar waveguide resonator. Considering the device as a potential quantum optical component in the microwave regime, we create a sensitive bifurcation amplifier and then demonstrate spectroscopy of other resonant modes via the intermode coupling. We find that the sensitivity of the device approaches within a factor two quantitative agreement with a quantum model by Dykman but is limited by a noise that has its source(s) on-chip.

Appl. Phys. Lett. 103, 063504 (2013)

doi: 10.1063/1.4818123