Speaker
Description
We show first-principles calculations and angle- and spin- resolved photoemission spectroscopy studies of a two-dimensional bilayer of 𝛽-antimonene supported on bulk bismuth selenide. The trivial insulator 𝛽-antimonene inherits the topological surface state of the substrate as a result of the topological proximity effect. The new topological state exhibits an unusually high, almost complete out-of-plane spin polarization within the substrate gap, that we explain by a symmetry-protected band crossing of spin-polarized surface states. The spin polarization can be finely and reversibly tuned from nearly full out-of-plane to nearly full in-plane by electron doping. Our findings pave the way towards advanced spintronics applications exploiting the giant out-of-plane spin polarization of topological surface states.
