Department of Physics, Institute of Physics, Budapest University of Technology and Economics, Müegyetem rkp. 3., H-1111 Budapest, Hungary.
MTA-BME Superconducting Nanoelectronics Momentum Research Group, Müegyetem rkp. 3., H-1111 Budapest, Hungary.
ACS Nano. 2023 Mar 28;17(6):5528-5535. doi: 10.1021/acsnano.2c10877. Epub 2023 Mar 13.
Understanding the microscopic origin of the gate-controlled supercurrent (GCS) in superconducting nanobridges is crucial for engineering superconducting switches suitable for a variety of electronic applications. The origin of GCS is controversial, and various mechanisms have been proposed to explain it. In this work, we have investigated the GCS in a Ta layer deposited on the surface of InAs nanowires. Comparison between switching current distributions at opposite gate polarities and between the gate dependence of two opposite side gates with different nanowire-gate spacings shows that the GCS is determined by the power dissipated by the gate leakage. We also found a substantial difference between the influence of the gate and elevated bath temperature on the magnetic field dependence of the supercurrent. Detailed analysis of the switching dynamics at high gate voltages shows that the device is driven into the multiple phase slips regime by high-energy fluctuations arising from the leakage current.
理解超导纳米桥上栅控超导电流（GCS）的微观起源对于工程学上设计适用于各种电子应用的超导开关至关重要。GCS 的起源存在争议，已经提出了各种机制来解释它。在这项工作中，我们研究了沉积在 InAs 纳米线表面的 Ta 层中的 GCS。在相反栅极极性下的开关电流分布之间以及具有不同纳米线-栅极间距的两个相反侧栅极的栅极依赖性之间进行比较，表明 GCS 由栅极泄漏耗散的功率决定。我们还发现栅极和升高的浴温对超导电流的磁场依赖性的影响有很大差异。在高栅极电压下对开关动力学的详细分析表明，器件被来自漏电流的高能涨落驱动进入多相滑移状态。
