Rashba-type spin splitting at Au(111) beyond the Fermi level: the other part of the story

Abstract

We present a combined experimental and theoretical study of spin-orbit-induced spin splittings in the unoccupied surface electronic structure of the prototypical Rashba system Au(111). Spin-and angle-resolved inversephotoemission measurements reveal a Rashba-type spin splitting in the unoccupied part of the L-gap surface state. With increasing momentum parallel to the surface, the spectral intensity is lowered and the spin splitting vanishes as the surface state approaches the band-gap boundary. Furthermore, we observe significantly spin-dependent peak positions and intensities for transitions between unoccupied sp-like bulk bands. Possible reasons for this behavior are considered: initial and final-state effects as well as the transition itself, which is controlled by selection rules depending on the symmetry of the involved states. Based on model calculations, we identify the initial states as origin of the observed Rashba-type spin effects in bulk transitions.

Momentum resolution in inverse photoemission

“…8. 55 Around θ = 8 • , a large intensity ratio between the two spin components can be observed. Figure 9(a) shows spectra for θ = 8 • , simulated for three different beam divergences.…”

“…21,55 The total energy resolution was found to be 450±50 meV (step 3). The photon counter is located in the plane perpendicular to the measurement plane, as defined by electron incidence direction and surface normal, at 45 • with respect to the electron incidence direction.…”

Spin polarization of surface states on W(1 1 0): Combined influence of spin–orbit interaction and hybridization

“…Rashba systems and topological insulators stimulate strong demand for direct observation of their band structure with separation of spin-up and -down states. Spinand angle-resolved photoemission spectroscopy (spin-ARPES) and inverse photoemission are the ideal tools to directly observe the spin-polarized electronic band structures, as demonstrated for noble metal surfaces [5,6], heavy metal atoms on semiconductor [7][8][9][10][11][12][13] and surface alloys [14,15].…”

Symmetry induced peculiar Rashba effect on thallium adsorbed Si(1 1 1) surfaces

“…(The effect of the geometric symmetry was not in the focus of the early studies [7][8][9][10][11][12][13][14][15][16][17][18], but is now considered to understand the RB effect in recent studies, e.g. [19][20][21], after our first report on symmetry induced peculiar RB effect (Ref.…”