Trapping in dilute quasi-one-dimensional systems

A model is developed for calculating the asymptotic trapping rate, by a sink, of an excitation migrating in a quasi-one-dimensional dilute system. The asymptotic behavior for the dilute limit differs considerably from that corresponding to a concentrated system. The migration is assumed to be incoherent and is described within the continuous time random walk approach. The competing roles of short range exchange coupling and of long range dipole–dipole coupling is also discussed using time scaling arguments.