LAUSR

Abstract It is shown, based on the density functional theory (DFT), that the spin splitting of surface electronic states induced by a Pb monolayer on the Ge(1 1 1)-1  ×  1 surface depends on the bonding structure of the Pb/Ge interface and may be either significant, ∼ 0.8 eV, (H3/T4) or completely suppressed (T1). It is also shown that for the former the bonding configuration facilitates an emergence of unquenched orbital angular momentum L along Γ -K-M direction, which then lifts the spin degeneracy of the electronic states through the spin-orbit coupling (SOC) of electrons in Pb. Along with the DFT data, we present a complementary analysis conducted withing the orbital Rashba framework, which provides an additional insight into the SOC-induced splitting.