Unraveling the spin structure of unoccupied states in Bi2Se3

Optická kontrola spinových prúdov v topologických izolátoroch je nová možnosť v spintronike. Na porozumenie týchto procesov je nutné zistiť elektrónovú štruktúru nad fermiho hladinou za použitia jednokrokového modelu a inverznej ARPES techniky The optical control of spin currents in topological surface states opens new perspectives in (opto-) spintronics. To understand these processes, a profound knowledge about the dispersion and the spin polarization of both the occupied and the unoccupied electronic states is required. We present a joint experimental and theoretical study on the unoccupied electronic states of the topological insulator Bi2Se3 . We discuss spin- and angle-resolved inverse-photoemission results in comparison with calculations for both the intrinsic band structure and, within the one-step model of (inverse) photoemission, the expected spectral intensities. This allows us to unravel the intrinsic spin texture of the unoccupied bands at the surface of Bi2 Se3.