Large Rashba spin splitting of a metallic surface-state band on a semiconductor surface.
The generation of spin-polarized electrons at room temperature is an essential step in developing semiconductor spintronic applications. To this end, we studied the electronic states of a Ge(111) surface, covered with a lead monolayer at a fractional coverage of 4/3, by angle-resolved photoelectron spectroscopy (ARPES), spin-resolved ARPES and first-principles electronic structure calculation. We demonstrate that a metallic surface-state band with a dominant Pb 6p character exhibits a large Rashba spin splitting of 200 meV and an effective mass of 0.028 m(e) at the Fermi level. This finding provides a material basis for the novel field of spin transport/accumulation on semiconductor surfaces. Charge density analysis of the surface state indicated that large spin splitting was induced by asymmetric charge distribution in close proximity to the nuclei of Pb atoms.
Yaji
Koichiro
K
Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
Ohtsubo
Yoshiyuki
Y
Hatta
Shinichiro
S
Okuyama
Hiroshi
H
Miyamoto
Koji
K
Okuda
Taichi
T
Kimura
Akio
A
Namatame
Hirofumi
H
Taniguchi
Masaki
M
Aruga
Tetsuya
T