Fermi level tuning of one-dimensional giant Rashba system on a semiconductor substrate: Bi/GaSb(110)-(2x1)

TL;DR

This study demonstrates tunable Fermi levels and giant Rashba spin splitting in a one-dimensional surface system on a semiconductor substrate, advancing potential spintronic applications.

Contribution

It introduces a method to tune the Fermi level of a 1D Rashba system on GaSb(110) using Ar-ion sputtering, revealing switchable metallic and semiconducting states.

Findings

Fermi level can be tuned in situ via Ar-ion sputtering.

The surface exhibits giant Rashba spin splitting with high Rashba parameters.

The system shows switchable metallic/semiconducting behavior.

Abstract

We fabricated spin-polarized surface electronic states with tunable Fermi level from semiconductor to low-dimensional metal in the Bi/GaSb(110)-(2$\times$1) surface using angle-resolved photoelectron spectroscopy (ARPES) and spin-resolved ARPES. The spin-polarized surface band of Bi/GaSb(110) exhibits quasi-one-dimensional character with the Rashba parameter $\alpha _{\rm R}$ of 4.1 and 2.6 eV\AA \ at the $\bar{\Gamma}$ and $\bar{\rm Y}$ points of the surface Brillouin zone, respectively. The Fermi level of the surface electronic state is tuned in situ by element-selective Ar-ion sputtering on the GaSb substrate. The giant Rashba-type spin splitting with switchable metallic/semiconducting character on semiconductor substrate makes this system a promising candidate for future researches in low-dimensional spintronic phenomena.