Generation and Control of Ultrafast Circular Photon Drag Current in Multilayer PtSe 2 Revealed Via Terahertz Emission
Generation and Control of Ultrafast Circular Photon Drag Current in Multilayer PtSe 2 Revealed Via Terahertz Emission
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通过太赫兹发射揭示多层 PtSe 2 中超快圆形光子拖曳电流的产生和控制
DOI：
10.1002/adom.202201881
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发表时间：
2022
影响因子：
9
通讯作者：
Zengxiu Zhao
中科院分区：
文献类型：
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作者：
Longhui Zhang;Dongwen Zhang;Fangrong Hu;Xinlong Xu;Qiyi Zhao;Xu Sun;Haizhong Wu;Zhihui Lü;Xiaowei Wang;Zengxiu Zhao
过渡金属二硫属化物（TMD）表面超快光电流的产生和控制对于先进光电器件的发展至关重要。详细了解超快光电流产生的机制是设计功能器件的主要需要。在这里，据报道，超快的光电流在多层PtSe2诱导的光子拖曳效应与高转换效率。特别地，在圆偏振激光激发下，产生各向异性的面内光子拖曳电流，导致由泵浦光束的螺旋度直接控制的椭圆偏振太赫兹（THz）辐射。此外，提出了一个新的模型，称为“太赫兹发射的圆形交流霍尔效应”（TECacHE）来揭示载流子输运过程。结果表明，由螺旋度控制的椭圆偏振太赫兹辐射的起源涉及纯圆光子拖曳流和洛伦兹力引起的延迟。此外，提出了超快三进制编码，并通过偏振太赫兹辐射进行了验证。这一结果不仅为研究表面超快光电流提供了一种新的非接触探测模型，而且也为研究太赫兹通信器件中层状TMD中的圆形光子拖曳电流提供了基础。
The generation and control of ultrafast photocurrents on the surface of transition‐metal dichalcogenides (TMDs) are essential for the development of advanced optoelectronic devices. A detailed understanding of the mechanism of ultrafast photocurrent generation is primarily needed to design functional devices. Here, it is reported that ultrafast photocurrents in multilayer PtSe2are induced by the photon drag effect with high conversion efficiency. Particularly, under circularly polarized laser excitation, anisotropic in‐plane photon drag currents are generated, leading to the elliptically polarized terahertz (THz) radiation directly controlled by the helicity of the pump beam. Furthermore, a new model called “THz emission by the circular ac Hall effect” (TECacHE) is proposed to unveil the carrier transport process. It is observed that the origins of elliptically polarized THz emission controlled by helicity involve the pure circular photon drag current and the retardation induced by the Lorentz force. Besides, ultrafast ternary encoding is proposed and demonstrated by polarized THz emission. The results not only provide a new contactless detection model to study surface ultrafast photocurrents but also afford a fundamental investigation of the circular photon drag current in layered TMDs for THz telecommunication devices.