论文标题
探测带有扭曲光的2D激子的自旋动力学
Probing spin dynamics of 2D excitons with twisted light
论文作者
论文摘要
我们通过使用光学涡流（OV）梁将光动量转移到质量中心中，提出了一种插入式载体式旋转式散射的机制。通过使用OV Beam的拓扑电荷改变光的分散，我们展示了一种独特的方法来控制激子的valley自旋翼散射速率。从我们的光致发光测量值中，我们证明了基于W的TMD中的谷体内散射率可以通过OV梁外部调节。光致发光强度与拓扑电荷的变化显示了交叉温度（> 150 K），表明涉及辐射重组，自旋flip散射和热弛豫的时间尺度之间的竞争。我们提出的利用结构化光束的技术可以打开一种新的方法来探索2D系统中激子的物理。
We propose a mechanism of intravalley spin-flip scattering in spin-valley coupled two dimensional systems by transferring momentum of light into exciton center of mass using optical vortex (OV) beams. By varying the dispersion of light using the topological charge of OV beam, we demonstrate a unique approach to control the intra-valley spin-flip scattering rate of excitons. From our photoluminescence measurements, we demonstrate that the intra-valley scattering rate in W-based TMDs can be tuned externally by OV beams. Variation of photoluminescence intensity with topological charges shows a crossover temperature (> 150 K), indicating competitions among time scales involving radiative recombination, spin-flip scattering, and thermal relaxations. Our proposed technique utilizing a structured light beam can open up a new approach to explore the physics of excitons in 2D systems.
