Berry dephasing due to diffusion in nuclear quadrupole resonance

Berry's phase can give rise to coherence dephasing in optically detected nuclear quadrupole resonance of gaseous Xe-131. Diffusion of xenon atoms around a toroidal container should cause incoherent acquisition of Berry's phase, with consequent loss of phase coherence between atoms. This leads to signal loss which is equivalent to spin relaxation. The rate of dephasing is calculated by two different methods: first, using an exact treatment of diffusion, and secondly, using average propagators. Berry dephasing is predicted to be an important relaxation mechanism in this system.