Magnetic resonance in semiconductors

半导体中的磁共振

• 批准号: 64100679
• 负责人: Dr. Vladislav Kataev
• 金额: --
• 依托单位: Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden (IFW) e.V.
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/64100679?language=en
• 关键词: Magnetic; resonance; semiconductors

In the second funding period we will continue electron spin resonance (ESR) studies aimed at the understanding of the long-living spin coherent electron states in III/V semiconductors and semiconductor heterostructures, such as GaAs. Along with using advanced but yet traditional ESR techniques based on the direct detection of the absorbed microwave radiation at the resonance, we will also focus on the electrically detected ESR (EDMR) schemes with the possibility of optical pumping. This approach will yield a strong increase of the sensitivity which is particularly important for studies of heterostuructures with small spin concentration. A combination of conventional ESR and EDMR techniques will enable complementary insights into the spin-dephasing and spin relaxation processes in particular regarding the interplay between optically excited spin-polarized electrons and donor states, impurities and dislocations. The influence of the carrier concentration on the spin coherence will be examined by studying sets of samples with different chemical doping but also in heterostructures where the electron concentration is controlled by the gate voltage. Finally, the spin properties of graphene will also be addressed by ESR and EDMR. Here the experiments will focus on the understanding of the relation between a very peculiar electronic structure and the dominant spin-spin interactions and relaxation paths of electrons in graphene.

在第二个资助期，我们将继续进行电子自旋共振（ESR）研究，旨在了解III/V半导体和半导体异质结构（如GaAs）中的长寿命自旋相干电子态。除了使用基于直接检测共振处吸收的微波辐射的先进但传统的ESR技术外，我们还将重点研究具有光泵浦可能性的电检测ESR （EDMR）方案。这种方法将大大提高灵敏度，这对于研究具有小自旋浓度的异质结构尤其重要。传统ESR和EDMR技术的结合将使自旋减相和自旋弛豫过程的互补见解，特别是关于光激发自旋极化电子与供体态、杂质和位错之间的相互作用。载流子浓度对自旋相干性的影响将通过研究不同化学掺杂的样品集以及电子浓度由栅极电压控制的异质结构来检验。最后，石墨烯的自旋性质也将通过ESR和EDMR进行研究。在这里，实验将集中于理解石墨烯中一个非常特殊的电子结构与主要的自旋-自旋相互作用和电子弛豫路径之间的关系。