Towards Cryogenic Quartz Oscillators: Coupling of a Bulk Acoustic Wave quartz resonator to a SQUID

Abstract

A system consisting of a SQUID amplifier coupled to a Bulk Acoustic Wave resonator is investigated experimentally from the small to large signal regimes. Both parallel and series connection topologies of the system are verified. The study reveals significant non-Duffing response that is associated with the nonlinear characteristics of Josephson junctions. The nonlinearity provides quasi-periodic structure of the spectrum in both incident power and frequency. The result gives an insight into the open loop behaviour of a future Cryogenic Quartz Oscillator operating with a SQUID amplifier as the active device.