Enhancement of Chiral-Induced Spin Selectivity via Circularly Polarized Light

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.