Hard Superconducting Gap in InSb Nanowires.
Hard Superconducting Gap in InSb Nanowires.
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DOI：
10.1021/acs.nanolett.7b00540
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发表时间：
2017-04-12
期刊：
影响因子：
10.8
通讯作者：
Kouwenhoven LP
中科院分区：
文献类型：
--
作者：
Gül Ö;Zhang H;de Vries FK;van Veen J;Zuo K;Mourik V;Conesa-Boj S;Nowak MP;van Woerkom DJ;Quintero-Pérez M;Cassidy MC;Geresdi A;Koelling S;Car D;Plissard SR;Bakkers EP;Kouwenhoven LP
拓扑超导是一种可以容纳马约拉纳模式的物质状态，马约拉纳模式是拓扑量子计算机的构建模块。许多实验平台预测显示这种拓扑状态依赖于邻近感应超导性。然而，获得拓扑特性需要诱导硬超导间隙，这对于大多数材料系统来说很难实现。我们系统地研究了 InSb 半导体纳米线和 NbTiN 超导体之间的界面如何影响感应超导性能。我们逐步提高界面的均匀性，同时确保与超导体的无障碍电接触，并在 InSb 纳米线中获得硬间隙。 NbTiN 的磁场稳定性使 InSb 纳米线能够在磁场（~0.5 T）存在下保持硬间隙和超电流，这是一维系统中拓扑超导性的要求。我们的研究为在半导体纳米线、二维电子气和拓扑绝缘体等各种实验平台中诱导超导提供了指导，并与拓扑超导和量子计算相关。
Topological superconductivity is a state of matter that can host Majorana modes, the building blocks of a topological quantum computer. Many experimental platforms predicted to show such a topological state rely on proximity-induced superconductivity. However, accessing the topological properties requires an induced hard superconducting gap, which is challenging to achieve for most material systems. We have systematically studied how the interface between an InSb semiconductor nanowire and a NbTiN superconductor affects the induced superconducting properties. Step by step, we improve the homogeneity of the interface while ensuring a barrier-free electrical contact to the superconductor and obtain a hard gap in the InSb nanowire. The magnetic field stability of NbTiN allows the InSb nanowire to maintain a hard gap and a supercurrent in the presence of magnetic fields (∼0.5 T), a requirement for topological superconductivity in one-dimensional systems. Our study provides a guideline to induce superconductivity in various experimental platforms such as semiconductor nanowires, two-dimensional electron gases, and topological insulators and holds relevance for topological superconductivity and quantum computation.