Thin-film hybrid structures of topological insulators with superconductors and ferromagnets: experiment and theory

在一个联合实验和理论努力中，我们研究了具有铁磁体或超导体的拓扑绝缘体的薄膜混合结构。我们的目标是开发通过隧道光谱和接近效应来检测和获取拓扑表面态的技术，用于自旋电子学中的器件应用。在实验方面，我们计划在Bi2Se3， Bi2Te3和补偿的Bi-(Te,Se)薄膜上生长绝缘体，铁磁体或超导体。我们还计划在六硼化物和Weyl半金属中研究新的拓扑材料。提出了一种简单的装置来探测和利用拓扑表面态的自旋轨道耦合性质。该器件将通过自旋相关隧道光谱、安德烈夫反射和自旋霍尔光谱进行表征。实验研究将辅以器件的理论研究，以检测拓扑表面状态，表征其性质，并控制自旋电流。理论研究将采用拓扑绝缘体、铁磁体和超导体混合结构的紧密结合模型的精确对角化。

In a joint experimental and theoretical effort we investigate thin-film hybrid structures of topological insulators with ferromagnets or superconductors. We aim to develop techniques to detect and access the topological surface states by tunnelling spectroscopy and proximity effects for device applications in spintronics. On the experimental side we plan to grow insulators, ferromagnets, or superconductors on Bi2Se3, Bi2Te3 and compensated Bi-(Te,Se) thin films. We also plan to investigate new topological materials within the hexaborides and Weyl semimetals. Simple devices are proposed to detect and exploit the spin-orbit coupled nature of the topological surface states. The devices will be characterized by spin-dependent tunnelling spectroscopy, Andreev reflection, and Spin-Hall spectroscopy. The experimental studies will be complemented by theoretical investigations of the devices in order to detect the topological surface states, characterize their properties, and control the spin current flow. The theoretical studies will employ exact diagonalization of tight-binding models for hybrid structures of topological insulators, ferromagnets, and superconductors.