Rashba split surface states in BiTeBr

TL;DR

This study uses density functional theory to analyze bulk and surface electronic structures of BiTeBr, revealing giant Rashba spin splitting on both Te- and Br-terminated surfaces, with the Te surface showing Rashba-type behavior.

Contribution

It provides the first detailed ab-initio analysis of surface states and Rashba splitting in ordered BiTeBr, highlighting the material's potential for spintronic applications.

Findings

Ordered BiTeBr is energetically more stable than disordered.

Both Te- and Br-terminated surfaces host surface states with giant spin-orbit splitting.

The Te-terminated surface exhibits Rashba-type spin splitting with lpha_R rac{2 eV\u00c5}{ ext{unit}}.

Abstract

Within density functional theory, we study bulk band structure and surface states of BiTeBr. We consider both ordered and disordered phases which differ in atomic order in the Te-Br sublattice. On the basis of relativistic ab-initio calculations, we show that the ordered BiTeBr is energetically preferable as compared with the disordered one. We demonstrate that both Te- and Br-terminated surfaces of the ordered BiTeBr hold surface states with a giant spin-orbit splitting. The Te-terminated surface-state spin splitting has the Rashba-type behavior with the coupling parameter \alpha_R ~ 2 eV\AA.