Anisotropic spin gaps in BiAg$_2$-Ag/Si(111)

TL;DR

This paper investigates the complex spin-polarized electronic structure of BiAg$_2$/Ag/Si(111) trilayers using high-resolution ARPES, revealing tunable spin gaps influenced by spin-orbit interactions and alkali metal deposition.

Contribution

It provides a detailed analysis combining ARPES data with calculations to understand and control spin gaps in BiAg$_2$/Ag/Si(111).

Findings

Identification of complex spin gaps in the electronic structure.

Demonstration of energy tuning of spin gaps via alkali metal deposition.

Correlation between spin-orbit interactions and the observed band structure.

Abstract

We present a detailed analysis of the band structure of the BiAg$_2$/Ag/Si(111) trilayer system by means of high resolution Angle Resolved Photoemission Spectroscopy (ARPES). BiAg2/Ag/Si(111) exhibits a complex spin polarized electronic structure due to giant spin-orbit interactions. We show that a complete set of constant energy ARPES maps, supplemented by a modified nearly free electron calculation, provides a unique insight into the structure of the spin polarized bands and spin gaps. We also show that the complex gap structure can be continuously tuned in energy by a controlled deposition of an alkali metal.