论文标题
锗量子井中Rashba效应的光学操纵
Optical manipulation of the Rashba effect in germanium quantum wells
论文作者
论文摘要
通过极化和时间分辨的光发光研究了GE/SI $ _ {0.15} $ ge $ _ {0.15} $ ge $ _ {0.85} $嵌入P-i-n二极管中的多个量子井的效果。除了由量子限制的Stark效应引起的相当大的红移外，还可以通过增加2kW/cm $^2 $范围的泵功率来获得直接过渡的圆极化度的三倍增强。这种明显的变化反映了自旋种群的有效调节，并通过对间接间隙转变的专门研究进一步支持。这项研究展示了一种可行的策略，可以通过非接触式光激发来设计自旋轨道哈密顿量，并为基于组IV异质结构中量子设备中旋转的电光操纵打开了道路。
The Rashba effect in Ge/Si$_{0.15}$Ge$_{0.85}$ multiple quantum wells embedded in a p-i-n diode is studied through polarization and time-resolved photoluminescence. In addition to a sizeable redshift arising from the quantum-confined Stark effect, a threefold enhancement of the circular polarization degree of the direct transition is obtained by increasing the pump power over a 2kW/cm$^2$ range. This marked variation reflects an efficient modulation of the spin population and is further supported by dedicated investigations of the indirect gap transition. This study demonstrates a viable strategy to engineer the spin-orbit Hamiltonian through contactless optical excitation and opens the way towards the electro-optical manipulation of spins in quantum devices based on group-IV heterostructures.
