Casimir-Polder Forces between Chiral Objects

TL;DR

This paper derives the chiral component of the Casimir-Polder potential, showing it depends on both particle and medium chirality, and explores its potential for enantiomer separation in cavity geometries.

Contribution

It provides a theoretical derivation of the chiral Casimir-Polder potential within macroscopic QED and demonstrates its application for enantiomer separation.

Findings

Chiral Casimir-Polder potential exists only if both particle and medium are chiral.

The chiral component can be attractive or repulsive depending on chirality.

Enantiomer separation is feasible when the molecule is initially excited and electric forces are suppressed.

Abstract

The chiral component of the Casimir-Polder potential is derived within the framework of macroscopic quantum electrodynamics. It is shown to exist only if the particle and the medium are both chiral. Furthermore, the chiral component of the Casimir-Polder potential can be attractive or repulsive, depending on the chirality of the molecule and the medium. The theory is applied to a cavity geometry in the non-retarded limit with the intention of enantiomer separation. For a ground state molecule the chiral component is dominated by the electric component and thus no explicit separation will happen. If the molecule is initially in an excited state the electric component of the Casimir-Polder force can be suppressed by an appropriate choice of material and the chiral component can select the molecule based on its chirality, allowing enantiomeric separation to occur.