Electrostatic control of phase slips in Ti Josephson nanotransistors

Unveiling Mechanisms of Electric Field Effects on Superconductors by Magnetic Field Response

“…The hysteresis is likely thermal in origin [27][28][29], and it disappears when T > 400 mK, which is consistent with an enhanced thermalization mediated by phonon coupling. As in similar experiments [1,2,[4][5][6][7][8], the critical current can be reduced, up to complete suppression at the critical gate voltage V C Gate ≈ 23 V. This is shown in Fig. 1c, for several temperatures.…”

“…The most striking effects: reduction and suppression of the critical supercurrent, have been broadly demonstrated in metallic nanowires [2] and Dayem bridges [3][4][5] made of titanium, aluminium and vanadium, as well as in aluminum-copper-aluminum Josephson junctions [6]. Moreover, recent experiments have probed the effect of electrostatic gating on the SC-phase in a SQUID [7], and on the nature of the current switching distributions in gated titanium Dayem bridges [8].…”

“…This remark is also consistent with the enhancement of non-thermal phase fluctuations that have been recently observed in the switching current distributions of Ti Dayem bridges. [8] Summary -We have investigated the suppression of supercurrent effected by the electric field combined with and inplane, or out-of-plane magnetic field, and ascertained that the two are weakly coupled: the critical magnetic fields are only affected for gate voltages close to the critical gate voltage. These findings are consistent with a microscopic, multiband model recently proposed [12], that posits that the electric field induces an orbital Rashba effect at the surface of metallic superconductors, ultimately leading to a transition to a normal or π state, suppressing the supercurrent.…”