Elalaily Tosson, Berke Martin, Lilja Ilari, Savin Alexander, Fülöp Gergő, Kupás Lőrinc, Kanne Thomas, Nygård Jesper, Makk Péter, Hakonen Pertti, Csonka Szabolcs
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.
Nat Commun. 2024 Oct 23;15(1):9157. doi: 10.1038/s41467-024-53224-2.
The observation of the gate-controlled supercurrent (GCS) effect in superconducting nanostructures increased the hopes for realizing a superconducting equivalent of semiconductor field-effect transistors. However, recent works attribute this effect to various leakage-based scenarios, giving rise to a debate on its origin. A proper understanding of the microscopic process underlying the GCS effect and the relevant time scales would be beneficial to evaluate the possible applications. In this work, we observed gate-induced two-level fluctuations between the superconducting state and normal state in Al/InAs nanowires (NWs). Noise correlation measurements show a strong correlation with leakage current fluctuations. The time-domain measurements show that these fluctuations have Poissonian statistics. Our detailed analysis of the leakage current measurements reveals that it is consistent with the stress-induced leakage current (SILC), in which inelastic tunneling with phonon generation is the predominant transport mechanism. Our findings shed light on the microscopic origin of the GCS effect and give deeper insight into the switching dynamics of the superconducting NW under the influence of the strong gate voltage.
在超导纳米结构中对门控超电流（GCS）效应的观察增加了实现半导体场效应晶体管超导等效物的希望。然而，最近的研究将这种效应归因于各种基于泄漏的情况，引发了关于其起源的争论。正确理解GCS效应背后的微观过程以及相关的时间尺度将有助于评估可能的应用。在这项工作中，我们观察到了Al/InAs纳米线（NWs）中门控诱导的超导态和正常态之间的两能级波动。噪声相关性测量显示与泄漏电流波动有很强的相关性。时域测量表明这些波动具有泊松统计特性。我们对泄漏电流测量的详细分析表明，它与应力诱导泄漏电流（SILC）一致，其中伴随着声子产生的非弹性隧穿是主要的输运机制。我们的发现揭示了GCS效应的微观起源，并更深入地洞察了在强门电压影响下超导NW的开关动力学。
