Robust spin-valley polarization in commensurate MoS2/graphene heterostructures

Article

关键词: MONOLAYER MOS2;    GRAPHENE;    RELAXATION;    TRANSPORT;    DEFECTS;    GROWTH;   

DOI  :  10.1103/PhysRevB.97.115445

来源: SCIE

【 摘 要 】

The investigation and control of quantum degrees of freedom (DoFs) of carriers lie at the heart of condensed-matter physics and next-generation electronics/optoelectronics. van der Waals heterostructures stacked from distinct two-dimensional (2D) crystals offer an unprecedented platform for combining the superior properties of individual 2D materials and manipulating spin, layer, and valley DoFs. MoS2/graphene heterostructures, harboring prominent spin-transport properties of graphene, giant spin-orbit coupling, and spin-valley polarization of MoS2, are predicted as a perfect venue for optospintronics. Here, we report the epitaxial growth of commensurate MoS2 on graphene with high quality by chemical vapor deposition, and demonstrate robust temperature-independent spin-valley polarization at off-resonant excitation. We further show that the helicity of B exciton is larger than that of A exciton, allowing the manipulation of spin bits in the commensurate heterostructures by both optical helicity and wavelength. Our results open a window for controlling spin DoF by light and pave a way for taking spin qubits as information carriers in the next-generation valley-controlled optospintronics.

【 授权许可】

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