The Rashba superconductor, in which spin-splitting bands become superconducting, is fascinating as a novel superconducting system in low dimensional systems. Here, we present the results of $\textit{in-situ}$ transport measurements on a Rashba-type surface state of the striped incommensurate (SIC) phase of a Pb atomic layer on Ge(111) surface with additional Pb islands/clusters on it. We found that two-step superconducting transitions at around 7 K and 3 K occurred. The latter superconducting transition is suggested to be induced at the non-superconducting Rashba SIC area because of the lateral proximity effect caused by the superconducting Pb clusters. Our results propose a new type of Rashba superconductor, which is a new platform to understand the Rashba superconducting systems.

中文翻译：

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在 Pb/Ge(111) 的 Rashba 型表面状态下的超导邻近效应

自旋分裂带变成超导的 Rashba 超导体作为低维系统中的一种新型超导系统令人着迷。在这里，我们展示了在带有额外 Pb 岛/簇的 Ge(111) 表面上 Pb 原子层的条纹不公度 (SIC) 相的 Rashba 型表面状态的 $\textit{in-situ}$ 传输测量结果在上面。我们发现在 7 K 和 3 K 附近发生了两步超导跃迁。由于超导 Pb 簇引起的横向邻近效应，建议在非超导 Rashba SIC 区域诱导后一种超导转变。我们的研究结果提出了一种新型的 Rashba 超导体，这是一个了解 Rashba 超导系统的新平台。