光控源漏极单层MoS_(2)场效应晶体管中自旋和谷极化输运  

Spin and valley polarization transport of monolayer MoS_(2)fieldeffect transistors modulated by optically controlled source and drain

作　　者：付旭日 郭亚涛 张明媚 任宝藏 袁瑞玚[1] FU XuRi;GUO YaTao;ZHANG MingMei;REN BaoCang;YUAN RuiYang(Department of Physics,Capital Normal University,Beijing 100048,China)

机构地区：[1]首都师范大学物理系,北京100048

出　　处：《中国科学：物理学、力学、天文学》2024年第12期195-204,共10页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(编号:11804236,11604226);北京市教育委员会科技发展计划项目(编号:KM201910028017,CIT-TCD201904080)资助。

摘　　要：新型二维材料由于其独特的自旋和谷电子学性质,成为制备量子集成器件的关键材料.光学调控是改变二维材料特性的有效方法,近年来利用圆偏振光来操控谷自由度备受关注.本文基于Floquet散射理和转移矩阵方法,研究了光控源漏极单层MoS_(2)场效应晶体管中自旋和谷极化输运特性.结果表明,与栅极光控单层MoS_(2)场效应晶体管结构相比,在源漏极施加光场时,自旋和谷极化输运对栅压的响应更灵敏,特别是调控栅压方向便可以实现由K′谷极化输运占主导地位转换为K谷过滤效应.更有趣的是,在此结构中,当电子低能入射时,100%理想谷极化几乎不依赖于量子结构的尺寸.这些新的发现为新型过渡金属硫化物场效应晶体管提供了潜在的应用价值.Due to the unique spin and valley electronic properties of new two-dimensional materials,it has become the key material for the preparation of quantum integrated devices.Optical modulation is an effective method to change the properties of two-dimensional materials.In recent years,the use of circularly polarized light to manipulate valley degrees of freedom has attracted a lot of attention.In this study,based on Floquet scattering theory and transfer matrix method,spin-and valley-polarized transport in monolayer MoS_(2)field-effect transistor(FET)with optically controlled source and drain have been investigated theoretically.The results show that,compared with light irradiated on gate,the spin-and valleypolarized transport exhibits greater sensitivity to the gate voltage when the source and drain are applied with light field.Especially,the polarized transport dominated by K′valley can be transformed into a K valley filtering effect by adjusting the gate direction.More interestingly,in this structure,the 100%valley polarization is almost independent of the size of the quantum structure when the electrons are incident with low energy.These new findings provide potential applications for the development of novel transition metal dichalcogenide FETs.

关 键 词：自旋-谷极化输运 圆偏振光 MoS_(2)场效应晶体管 

分 类 号：TN386[电子电信—物理电子学]