Artificial Topological Superconductor by the Proximity Effect
Artificial Topological Superconductor by the Proximity Effect
复制标题
利用邻近效应的人工拓扑超导体
DOI：
10.1103/physrevlett.112.217001
复制
发表时间：
2014-05-30
影响因子：
8.6
通讯作者：
Jia, Jin-Feng
中科院分区：
文献类型：
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作者：
Xu, Jin-Peng;Liu, Canhua;Jia, Jin-Feng
拓扑超导体（TSCs）具有完整的体隙和由马约拉纳费米子组成的无隙表面态，在容错拓扑量子计算中具有潜在的应用前景。由于TSC在自然界中非常罕见，研究TSC的另一种方法是通过邻近效应（PE）1-4人工地将超导性引入拓扑绝缘体（TI）的表面状态。本文报道了首次在Bi2Te3/NbSe2薄膜中PE诱导TSC的实验实现，通过扫描隧道显微镜探测的态密度证明了这一点。我们观察到拓扑绝缘体表面的Abrikosov涡旋和低能束缚态，以及超导相干长度与薄膜厚度和磁场的关系，这些都归因于拓扑表面态的超导性。这项工作证明了在超导涡旋内制造单个马约拉纳费米子的TSC的实际可行性，并完成了在PE诱导的TSC中寻找马约拉纳费米子的先决步骤。
Topological superconductors (TSCs) have a full gap in the bulk and gapless surface states consisting of Majorana fermions, which have potential applications in fault-tolerant topological quantum computation. Because TSCs are very rare in nature, an alternative way to study the TSC is to artificially introduce superconductivity into the surface states of a topological insulator (TI) through proximity effect (PE)1-4. Here we report the first experimental realization of the PE induced TSC in Bi2Te3/NbSe2 thin films as demonstrated by the density of states probed using scanning tunneling microscope. We observe Abrikosov vortices and lower energy bound states on the surface of topological insulator and the dependence of superconducting coherence length on the film thickness and magnetic field, which are attributed to the superconductivity in the topological surface states. This work demonstrates the practical feasibility of fabricating a TSC with individual Majorana fermions inside superconducting vortex as predicted in theory and accomplishes the pre-requisite step towards searching for Majorana fermions in the PE induced TSCs.