Controlled charge and spin currents in surface states of a toplogical insulator

本项目研究了拓扑绝缘体(TI)中表面态输运的基本性质。在该项目的第一部分，光刻器件的制备起着主导作用。静电清洁表面是研究TI系统输运的前提。对于这个项目的第二部分，有非常高质量的样品可用，专用的光刻工艺将使我们能够制造出显示未受干扰的表面态传输的器件。在这个项目中，我们将继续研究2DTI螺旋边缘通道中的输运，特别是通过施加人工散射势、外磁场和不同温度引入的对杂质、声子和电子-电子散射的稳定性。此外，高质量的3DTI样品和制造技术的可获得性为探索自旋动量锁定的2D Dirac电子的基本输运性质打开了可能性。这两个部分的目标都是设备概念用于自旋电子应用的可行性，这是一个长期以来一直渴望实现的目标，但到目前为止还没有取得重大进展。然而，这个目标现在在这个项目中已经成为一个现实的前景。

This project addresses the fundamental properties of surface state transport in a topological insulator (TI). During the first part of this project the lithographic device preparation played the dominant role. Electrostatically clean surfaces are the prerequisite for the investigation of transport in TI systems. For the second part of this project samples of very high quality are available and dedicated lithographic processes will allow us to fabricated devices which show the undisturbed surface state transport. In this project we will continue to investigate the transport in helical edge channels of a 2D TI and here especially the stability against impurity, phonon and electron-electron scattering introduced by applying artificial scattering potential, external magnetic field and various temperatures. Furthermore, the availability of high quality 3D TI samples and fabrication technologies opens up the possibility to explore the fundamental transport properties of spin-momentum locked 2D Dirac electrons. Both parts are aiming at the feasibility of device concepts for spintronic applications, a goal which is aspired since long but where no significant progress has been achieved so far. This goal however has become a realistic prospect now within this project.