Multimode Operation of a Superconducting Nanowire Switch in the Nanosecond Regime

Superconducting circuits are promising candidates for future computational architectures; however, practical applications require fast operation. Here, we demonstrate fast, gate-based switching of an Al nanowire-based superconducting switch in time-domain experiments. We apply voltage pulses to the gate while monitoring the microwave transmission of the device. Utilizing the usual leakage-based operation, these measurements yield a fast, 1−2 ns switching time to the normal state, possibly limited by the bandwidth of our setup, and a 15−20 ns delay in the normal to superconducting transition. However, having a significant capacitance between the gate and the device allows for a different operation, where the displacement current, induced by the fast gate pulses, drives the transition. The switching from superconducting to the normal state yields a similar fast time scale, while in the opposite direction the switching is significantly faster (4−6 ns) than the leakage-based operation, which may be further improved by a better thermal design. The measured short time scales and the displacement current-based switching operation will be important for future fast and low-power-consumption applications.