Non-adiabatic phenomena in a coupled SQUID ring-tank circuit system in the strongly hysteretic regime

In this paper we consider new and remarkable dynamical behaviour display ed by a strongly hysteretic SQUID (Superconducting Quantum Interference device) - a single Josephson weak link enclosed by a thick superconducting ring inductively coupled to a radio frequency (rf) parallel LC tank circuit resonator. Experimentally, Ne show that in the strongly hysteretic regime this coupled system can display remarkable level structure in its dynamics, quite different to that normally associated with rf driven SQUID ring systems. We demonstrate theoretically that this level structure arises when the SQUID ring responds non-adiabatically to time dependent changes in its potential, i.e. so that the ring no longer stays at or very close to the minimum in this potential as it changes in time.