Casimir force between ideal metal plates in a chiral vacuum

We calculate the Casimir force between two parallel ideal metal plates when there is an intervening chiral medium present. Making use of methods of quantum statistical mechanics, we show how the force can be found in a simple and compact way. The expression for the force is in agreement with that obtained recently by Jiang and Wilczek (Phys Rev B 99:125403, 2019), in their case with the use of Green function methods.