Pinch resonances in a radio-frequency-driven superconducting-quantum-interference-device ring-resonator system - art. no. 016208

In this paper we present experimental data on the frequency domain response of a superconducting-quantum-interference-device ring (a Josephson weak li nk enclosed by a thick superconducting ring) coupled to a radio frequency t ank circuit resonator. We show that with the ring weakly hysteretic the res onance line shape of this coupled system can display opposed fold bifurcati ons that appear to touch (pinch off). We. demonstrate that for appropriate circuit parameters these pinchoff line shapes exist as solutions of the non linear equations of motion for the system.