Tunable Manipulation of Enantiomers by Vector Exceptional Points

It is very important to achieve controllable manipulations of enantiomers in the fields of chemistry and biology. Here, we propose a method for realizing the effect of separating and purifying the opposite enantiomers by changing the relative phase of the incident lights at different times based on photonic crystal slabs sustaining vector exceptional points. Our calculations show that the large gradient of chiral optical fields can be generated with two beams of lights illuminating the photonic crystal slab from opposite directions at the vector exceptional points, and the direction of enhanced chiral optical force can be adjusted by changing the relative phase for the two beams of circularly polarized lights, making the controllable capture and separation of enantiomers achievable. Furthermore, we demonstrate the feasibility and efficiency of this design based on particle tracking simulations. This kind of chiral reversal of the separated enantiomers driven by light based on vector exceptional points is unprecedented. Our findings provide a possible route toward enantiopure syntheses in controllable all-optical platforms.