Sign of the Casimir force between two bodies coupled to a Dirac field

Abstract

We apply the result of Kenneth and Klich [Phys. Rev. Lett. 97, 160401 (2006)] to derive a theorem for two objects coupled to a Dirac field. We demonstrate that a sufficient condition for the Casimir interaction to be repulsive is for their geometric configuration to be odd under the same reflection operation considered in that work.