Enhancement of Chiral-Induced Spin Selectivity via Circularly Polarized Light

TL;DR

This paper presents a non-perturbative theoretical approach demonstrating how circularly polarized light can significantly enhance chiral-induced spin selectivity effects, potentially improving spin polarization in molecular spintronics.

Contribution

The study introduces a Floquet electronic friction model to show how strong light-matter interactions under circularly polarized light can boost spin polarization in chiral molecules.

Findings

Spin polarization can be enhanced to over 90% with CP light.

Nonadiabatic effects combined with light-matter interactions are key to the enhancement.

The model provides a basis for experimental control of spin currents in chiral systems.

Abstract

The notion of chiral-induced spin selectivity (CISS) has attracted intensive research interest recently. However, the practical applications of the CISS effects face challenges due to relatively low spin polarization. In this Letter, we propose a non-perturbative theory illustrating how circularly polarized (CP) light enhances CISS effects through strong light-matter interactions. We introduce a Floquet electronic friction model to study the nonadiabatic dynamics and spin transport through a chiral molecule in a molecule junction subjected to external driving. Our results show that the interplay of the nonadiabatic effects and light-matter interactions can significantly ($>90\%$) enhance electron spin polarization under CP light. Our predictions can be very useful in experiments for using CP light to control spin current in chiral molecular junctions.