# Proximity induced spin-valley polarization in silicene/germanene on F-doped WS$_2$

## TL;DR

This paper demonstrates that F-doped WS2 substrate induces spin-valley polarization in silicene and germanene through proximity effects, opening a band gap and enhancing spin-orbit coupling, which is validated by first-principles calculations.

## Contribution

It introduces F-doped WS2 as a substrate that induces spin-valley polarization in silicene/germanene without detrimental effects, via proximity effects.

## Key findings

- F-doped WS2 opens a band gap in silicene/germanene.
- F doping induces spin polarization in WS2.
- Proximity effects enhance spin-valley polarization.

## Abstract

Silicene and germanene are key materials for the field of valleytronics. However, interaction with the substrate, which is necessary to support the electronically active medium, becomes a major obstacle. In the present work, we propose a substrate (F-doped WS$_2$) that avoids detrimental effects and at the same time induces the required valley polarization, so that no further steps are needed for this purpose. The behavior is explained by proximity effects on silicene/germanene, as demonstrated by first-principles calculations. Broken inversion symmetry due to the presence of WS$_2$ opens a substantial band gap in silicene/germanene. F doping of WS$_2$ results in spin polarization, which, in conjunction with proximity-enhanced spin orbit coupling, creates sizable spin-valley polarization.