Generation of spin-polarized hot electrons at topological insulators surfaces by scattering from collective charge excitations

Abstract

A key feature of topological insulators, such as Bi2Se3 is their protected electronic surface states where the direction of spin is locked to their momentum. Here, using spin-polarized electron energy loss spectroscopy, the authors demonstrate that collective charge excitations can initiate spin-dependent electron scattering at the surface of Bi2Se3, and this occurs for both the elastic and inelastic scattering channels.