Topological Surface States with Persistent High Spin Polarization across Dirac Point in Bi$_{2}$Te$_{2}$Se and Bi$_{2}$Se$_{2}$Te

TL;DR

This study reveals that Bi$_{2}$Te$_{2}$Se and Bi$_{2}$Se$_{2}$Te topological insulators exhibit persistent high spin polarization across the Dirac point, enhancing their potential for spintronic applications.

Contribution

First demonstration of persistent high spin polarization across the Dirac point in these topological insulators using advanced spin-resolved photoemission spectroscopy.

Findings

High spin polarization observed in both compounds.

Spin textures remain helical across the Dirac point.

Potential for spintronic device applications.

Abstract

Helical spin textures with the marked spin polarizations of topological surface states have been firstly unveiled by the state-of-the-art spin- and angle-resolved photoemission spectroscopy for two promising topological insulators Bi$_2$Te$_2$Se and Bi$_2$Se$_2$Te. The highly spin-polarized natures are found to be persistent across the Dirac point in both compounds. This novel finding paves a pathway to extending their utilization of topological surface state for future spintronic applications.