# Spin-polarized quasi 1D state with finite bandgap on the Bi/InSb(001) surface

## TL;DR

This study reports the discovery of spin-polarized quasi-one-dimensional electronic states with a finite bandgap on Bi/InSb(001) surfaces, revealing potential for spintronic applications due to their unique dispersion and spin properties.

## Contribution

It demonstrates the existence of spin-polarized 1D states with a finite bandgap on Bi/InSb(001), combining ARPES and spin-resolved measurements to reveal their dispersion and spin orientation.

## Key findings

- 1D states exhibit Dirac-cone-like dispersion with a 150 meV bandgap.
- Spin polarization of both occupied and unoccupied states was observed.
- Spin orientation inverts with wave vector direction, indicating spin-momentum locking.

## Abstract

One-dimensional (1D) electronic states were discovered on 1D surface atomic structure of Bi fabricated on semiconductor InSb(001) substrates by angle-resolved photoelectron spectroscopy (ARPES). The 1D state showed steep, Dirac-cone-like dispersion along the 1D atomic structure with a finite direct bandgap opening as large as 150 meV. Moreover, spin-resolved ARPES revealed the spin polarization of the 1D unoccupied states as well as that of the occupied states, the orientation of which inverted depending on the wave vector direction parallel to the 1D array on the surface. These results reveal that a spin-polarized quasi-1D carrier was realized on the surface of 1D Bi with highly efficient backscattering suppression, showing promise for use in future spintronic and energy-saving devices.