Photocurrents and phase coherent transport in InAs:Mn

在这个项目中，我们计划探索新的自旋轨道相互作用和拓扑量子效应。InAs：Mn异质结构含有二维空穴气（2DHG）。除了大的自旋-轨道耦合之外，该材料的特征在于二维空穴与自旋为5/2的内置Mn离子之间的交换耦合。该项目涉及InAs：Mn异质结构的生长和优化，通过太赫兹感应光电流表征自旋轨道相互作用（即Rashba和Dresselhaus自旋轨道耦合强度的分离）以及系统研究源于几何相位的量子干涉效应。为此目的，将由InAs：Mn制成纳米级环形结构，其中Rashba系数α可以通过施加电场来调节。虽然自旋轨道相互作用产生了额外的阶段，如Aharonov-Anandan和Aharonov-Casher阶段，这是一个开放的问题，如何在这个系统中的交换耦合改变这些相位相干现象。在这个项目中，我们的目标是详细了解InAs：Mn二维空穴系统和更深入地了解交换相互作用的拓扑量子效应的作用。

Within this project we plan to explore spin-orbit interaction and topological quantum effects in novel. InAs:Mn heterostructures containing a two-dimensional hole gas (2DHG). In addition to the large spin-orbit coupling the material is characterized by exchange coupling between the two-dimensional holes and the built in Mn ions with spin 5/2. The project involves the growth and optimization of InAs:Mn heterostructures, the characterization of spin-orbit interaction (i.e. the separation of Rashbaand Dresselhaus spin-orbit coupling strength) by means of terahertz induced photocurrents and the systematic investigation of quantum interference effects which stem from geometric phases. For this purpose nanoscale ring structures will be made out of InAs:Mn in which the Rashba coefficient α can be tuned by means of an applied electric field. While spin orbit interaction gives rise to additional phases like the Aharonov-Anandan and the Aharonov-Casher phase it is an open issue how exchange coupling in this systems alters these phase coherent phenomena. Within this project we aim at a detailed understanding of the InAs:Mn two-dimensional hole system and a deeper insight into the role of exchange interaction for topological quantum effects.