On a model for rotational tunneling with a $$C_{6}$$-space-time symmetric analog

Abstract

We analyze the simple model of a rigid rotor with $$C_{3}$$ symmetry and show that the use of parity simplifies considerably the calculation of its eigenvalues. We also consider a non-Hermitian space-time-symmetric counterpart that exhibits real eigenvalues and determine the exceptional point at which the antiunitary symmetry is broken.