First-principles Study of Rashba Effect in Ultra-thin Bismuth Surface Alloys

TL;DR

This study uses first-principles density functional calculations to analyze the Rashba effect in ultra-thin bismuth surface alloys with various metals, revealing trends in Rashba coefficients that could inform spintronic material design.

Contribution

It provides the first-principles analysis of Rashba effects in Bi surface alloys with multiple metals, predicting trends in Rashba parameters for different alloy compositions.

Findings

Rashba parameters for Bi/Ag align with previous results.

Predicted Rashba coefficient trends for noble metals: Bi/Ag > Bi/Cu > Bi/Au.

Predicted Rashba coefficient trends for transition metals: Bi/Ni > Bi/Co > Bi/Fe.

Abstract

We performed density functional calculations for ultra-thin bismuth surface alloys: surface alloys of bismuth and face-centered cubic metals Bi/$M$(111)-$(\sqrt{3}\times\sqrt{3})R30\deg$ ($M$=Cu, Ag, Au, Ni, Co, and Fe). Our calculated Rashba parameters for the Bi/Ag are consistent with the previous experimental and theoretical results. We predicted a trend in the Rashba coefficients $\alpha_R$ of bands around the Fermi energy for noble metals as follows: Bi/Ag > Bi/Cu > Bi/Au. As for the transition metals, there is a trend in $\alpha_R$: Bi/Ni > Bi/Co > Bi/Fe. Our finding may lead to design efficient spin-charge conversion materials.