Photogalvanic Effect in Silicene

TL;DR

This paper investigates the photogalvanic effect in silicene, revealing how electric fields and spin-orbit coupling induce spin-valley locking, resulting in spin-polarized photocurrents, highlighting silicene's potential in spintronic applications.

Contribution

It provides a semi-classical analysis of the photogalvanic effect in silicene beyond the Dirac approximation, emphasizing the role of electric fields and spin-orbit coupling.

Findings

Electric field acts as a pseudo-magnetic field breaking inversion symmetry.

Spin-valley locking enables spin-polarized photocurrent injection.

Silicene exhibits superior spintronic properties compared to graphene.

Abstract

Silicene has introduced itself as an outstanding novel material, which seeks its meritorious place among common spintronic devices like Cu and Ag. In this work, photogalvanic effect in silicene is studied within the semi-classical approach and beyond Dirac point approximation. Normal electric field plays the role of effective pseudo-magnetic field which breaks the inversion symmetry and splits the conduction and valence bands. The interplay between this external field and intrinsic spin-orbit coupling provides spin-valley locking in silicene. Spin-valley locking in silicene makes this material superior to its carbon counterpart, graphene. Since the absorption of the polarized photons is not equivalent at both of the valleys, spin-valley locking leads to a spin-polarized photocurrent injection.