Robustly protected carrier spin relaxation in electrostatically doped transition-metal dichalcogenides

Article

关键词: WEAK-LOCALIZATION;    QUANTUM-WELLS;    VALLEY POLARIZATION;    ORBIT INTERACTION;    MONOLAYER MOS2;    TRANSISTORS;    SEMICONDUCTOR;    COHERENCE;    ELECTRONS;    WS2;   

DOI  :  10.1103/PhysRevB.95.205302

来源: SCIE

【 摘 要 】

Transition-metal dichalcogenides are unique semiconductors because of their exclusive coupling between the spin and the valley degrees of freedom. The spin flip simultaneously requires a large amount of the crystal momentum variation; hence most of the carrier scattering is expected to be the spin-conserving intravalley scattering. Analysis of the quantum interference effects on the magnetoconductivity in WSe2, MoSe2, andMoS(2) reveals that the spin-relaxation time is orders of magnitude longer than the carrier momentum scattering time, indicating that the valley-spin coupling robustly protects the spin polarization from carrier scatterings. In addition, the electron-spin-relaxation time of MoSe2 is found to be anomalously short compared to other members, which is likely the origin of the ultrafast valley scattering of excitons in MoSe2.

【 授权许可】

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