Photogalvanic effects in HgTe quantum well structures and all-electric detection of radiation polarization

HgTe 量子阱结构中的光电效应和辐射偏振的全电检测

• 批准号: 5456164
• 负责人: Professor Dr. Sergey Ganichev
• 金额: --
• 依托单位: Institut für Experimentelle und Angewandte Physik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2005
• 资助国家: 德国
• 起止时间: 2004-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5456164?language=en
• 关键词: Photogalvanic; effects; HgTe; quantum; well

Lately, there is much interest in the use of the spin of carriers in semiconductor quantum well structures together with their charge to realize novel concepts like spintronics and spin-optoelectronics. One of the new aspects of spin-optoelectronics is the generation of spin photocurrents in low symmetric quantum structures. In our previous work carried out on II-V semiconductor structures it has been shown that a non-equilibrium spin polarization of electrons in a quantum well is inevitably linked with an electric current in the well if some general symmetry requirements are met. This project is directed towards the investigation of spin transport in SiGe quantum structures applying these phenomena. Two types of spin photocurrents should be studied: the circular photogalvanic effect and the spin-galvanic effect. While the circular photgalvanic effect is already observed in p-type SiGe structures, to the CPGE in n-type materials and to the spin-galvanic effect in SiGe quantum wells there are only preliminary data. Experiments will be paralleled by theoretical development. As a result we should get insight into the nature of these new spin-related phenomena. Applying the spin photocurrents the basic information on spin transport in SiGe quantum wells comprising the spin related details of the band structure of quantum wells and spin relaxation processes should be obtained. Experiments should be carried out using infrared radiation which results in the monopolar spin orientation being very close to the condition of the electrical spin injection. These data obtained for SiGe structures are of particular importance because this material is a promising system for spin-based electronics. One of the further aims of this project is to develop a new spin-optoelectronic device: a fast room temperature helicity sensitive detector for infrared radiation with subnanosecond time resolution.

最近，人们对利用半导体量子阱结构中载流子的自旋及其电荷来实现自旋电子学和自旋光电子学等新概念产生了浓厚的兴趣。自旋光电子学的一个新方面是在低对称量子结构中产生自旋光电流。在我们以前对II-V族半导体结构进行的工作中，已经表明，如果满足某些一般对称性要求，量子阱中电子的非平衡自旋极化不可避免地与阱中的电流相关联。本项目旨在利用这些现象研究SiGe量子结构中的自旋输运。研究自旋光电流有两种类型：环形光电流效应和自旋-光电流效应。虽然在p型SiGe结构中已经观察到了圆形光电流效应，但对于n型材料中的CPGE和SiGe量子威尔斯中的自旋-光电流效应，只有初步的数据。实验将被理论的发展所证实。因此，我们应该深入了解这些新的自旋相关现象的本质。应用自旋光电流，应该获得关于SiGe量子威尔斯中自旋输运的基本信息，包括量子威尔斯的能带结构和自旋弛豫过程的自旋相关细节。实验应该使用红外辐射进行，这导致单极自旋取向非常接近电自旋注入的条件。这些数据获得的SiGe结构是特别重要的，因为这种材料是一个有前途的系统自旋为基础的电子。该项目的进一步目标之一是开发一种新的自旋光电器件：一种用于红外辐射的具有亚纳秒时间分辨率的快速室温螺旋度敏感探测器。