Relativistic response and novel spin-charge plasmon at the Tl/Si(111) surface

Article

关键词: DENSITY-FUNCTIONAL THEORY;    TOPOLOGICAL INSULATORS;    DIELECTRIC-CONSTANT;    METAL-SURFACES;    ENERGY;    EXCITATION;   

DOI  :  10.1103/PhysRevB.96.035416

来源: SCIE

【 摘 要 】

We present a comprehensive ab initio analysis of the spin-charge correlations at the Tl/Si(111) surface, where the spin-orbit interaction is so strong that a detailed treatment of the noncollinear electron spin appears decisive for the correct description of the response properties. The relativistic limit enforces a unified treatment of the spin and charge densities as a four-vector, and the response function acquires then a 4 x 4 tensor structure. Our all-electron implementation allows us to resolve the real-space structure of the possible collective modes, and demonstrates the emergence of a novel collective excitation combining transverse-spin and ordinary charge oscillations of a similar order of magnitude, whose spin character is strongly enhanced as we approach the q -> 0 momentum limit.

【 授权许可】

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