Peculiar Spin Texture Induced by Spin-Orbit Interaction in Solid(Research)

Abstract

We have uncovered that the d-electron-based surface state of W(110) shows a Dirac-cone-like feature with remarkable spin texture within a spin-orbit-induced symmetry gap. The C_<2v> symmetry of W(110) surface strongly influences this spin-polarized Dirac-cone-like surface state. Consequently, the Dirac-cone-like feature appears along <ΓH>^^^- and <ΓS>^^^-, while it is strongly deformed along <ΓN>^^^-. The observed results are well described by the model calculations based on an effective Hamiltonian with C_<2v>. The spin texture of the flattened Dirac cone obtained from model calculations is aligned along <ΓN>^^^- direction. This situation would substantially enhance the spin relaxation time. This finding opens a new avenue in the study of d-electron-based topological insulator with C_<2v> symmetry.