Measuring the switching current of a superconducting single electron transistor in a tunable dissipative environment

We experimentally investigated the switching current Isw of a superconducting single electron transistor (sSET), with competitive Josephson coupling energy EJ and charging energy Ec, in an in situ tunable dissipative environment. At low temperature, averaged Isw shows a clear 1e periodic function of gate induced charge on the island. The relative contrast of this oscillation increases when EJ/Ec is lowered. Increasing dissipation reduce the quantum fluctuations of the phase across the sSET, leading to an increased Isw. \ua9 Published under licence by IOP Publishing Ltd.Peer reviewed: YesNRC publication: Ye