A band structure scenario for the giant spin-orbit splitting observed at the Bi/Si(111) interface

摘要

The Bi/Si(111) (sqrt{3} x sqrt{3})R30 trimer phase offers a prime example ofa giant spin-orbit splitting of the electronic states at the interface with asemiconducting substrate. We have performed a detailed angle-resolvedphotoemission (ARPES) study to clarify the complex topology of the hybridinterface bands. The analysis of the ARPES data, guided by a modeltight-binding calculation, reveals a previously unexplored mechanism at theorigin of the giant spin-orbit splitting, which relies primarily on theunderlying band structure. We anticipate that other similar interfacescharacterized by trimer structures could also exhibit a large effect.