光波驱动Bi_(2)Se_(3)拓扑表面态的超快电流产生  

Light Wave Induced Ultrafast Current Generation from Bi_(2)Se_(3)Topological Surface States

作　　者：马泽阳 刘灿东[2] Ma Zeyang;Liu Candong(College of Science,University of Shanghai for Science and Technology,Shanghai 200093,China;State Key Laboratory of High Field Laser Physics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China)

机构地区：[1]上海理工大学理学院,上海200093 [2]中国科学院上海光学精密机械研究所强场激光物理国家重点实验室,上海201800

出　　处：《激光与光电子学进展》2025年第1期321-328,共8页Laser & Optoelectronics Progress

基　　金：国家重点研究计划(2022YFE0204800);国家自然科学基金(12174413);中国科学院稳定支持基础研究领域青年团队计划(YSBR-091)。

摘　　要：基于紧束缚近似电子结构模型,结合含时密度矩阵的动力学演化方法,从理论上研究了周期量级飞秒激光驱动拓扑材料Bi_(2)Se_(3)产生的超快光电流过程。研究结果表明:光电流对电场载波形状的改变非常敏感,体现出对激光脉冲载波包络相位(CEP)的强烈依赖性。随着驱动激光强度的增高,电子动力学过程进入强场相互作用区域,超快电流随CEP的改变呈现出显著不同的变化规律,反映了拓扑材料在超快时间尺度下与众不同的光学响应现象。尤其重要的是,在垂直于驱动光偏振方向上也能产生明显有着CEP依赖性的光电流。进一步分析表明,这种现象与拓扑表面态密切相关,在拓扑材料体态中无法观察到。研究结果有望帮助探索拓扑绝缘体表面态的超快电子运动特性,并为未来光频运转的光学器件的设计提供一定的理论指导。Based on a tight-binding approximation electronic structure model and incorporation of the dynamic evolution method of the time-dependent density matrix equation,in this study,the ultrafast photo-current generation process is theoretically investigated from the topological material Bi_(2)Se_(3)driven by few-cycle femtosecond laser pulse.The research results demonstrate that the light current is highly sensitive to change in the carrier waveform of the electric field,exhibiting a strong dependence on the carrier envelope phase(CEP)of the laser pulse.As the driving laser intensity increases,the electron dynamics enter a strong field interaction regime,and the ultrafast current shows significantly different variations with changes in CEP,reflecting distinct optical response phenomena of topological materials on ultrafast time scales.Specifically,it is crucial that the significant CEP-dependent light current can also be generated in the direction perpendicular to the polarization direction of the driving light.Further analysis shows that this phenomenon is closely related to topological surface states and cannot be observed in bulk states of topological materials.The research results can aid in exploring the ultrafast electron motion characteristics of surface states of topological insulators and offer theoretical guidance for the future design of optical devices operating at optical frequencies.

关 键 词：拓扑材料 光电流 载波包络相位 强场激光 表面态 

分 类 号：O437[机械工程—光学工程]