Ultrafast and time-resolved Raman spectroscopy of spin excitations in p-doped semiconductor heterostructures

研究了GaAs-AlGaAs量子阱系统中空穴的自旋动力学和元激发动力学。在该项目的一部分，一个很长的空穴自旋相干性，我们最近在低温下观察到的，应研究其依赖于带混合，对称性的限制势和远程掺杂剂的存在。利用时间分辨的法拉第/克尔实验、时间分辨的光致发光和共振自旋放大技术，我们将探索在低温和小磁场下空穴自旋初始化的机制和空穴自旋相干性的极限。在第二个项目部分中，我们通过拉曼光谱研究了空穴的自旋密度激发。在这里，这些电荷中性自旋激发相对于不同的晶体方向和动力学的激发的各向异性应进行探讨。

We investigate the spin dynamics of holes and the dynamics of elementary excitations of holes in undoped and p-doped GaAs-AlGaAs quantum-well systems. In one part of the project, a very long hole-spin coherence, which we have observed recently at low temperatures, shall be studied concerning its dependence on band mixing, symmetry of the confining potential and presence of remote dopants. Employing time-resolved Faraday/Kerr experiments, time-resolved photoluminescence and resonant spin amplification, we will explore hole spin initialization mechanisms and the limits of hole spin coherence at low temperatures and small magnetic fields. In a second project part, we investigate spin-density excitations of holes via Raman spectroscopy. Here, the anisotropy of these charge-neutral spin excitations with respect to different crystal directions and the dynamics of the excitations shall be explored.