Direct simulation of non-linear interparticle collisional relaxation of ensembles of two-level systems Original Research Article

In this work, we study the particle kinetics of self-interacting two-level systems in gas phase. The translational relaxation is described by means of the direct simulation Monte Carlo method. The quantum state of the ensemble is described by a distribution function on the Riemann sphere as suggested in a recent paper [S. Longo, D. Bruno, M. Capitelli, P. Minelli, Chem. Phys. Lett. 316 (2000) 311]. Detailed results are presented for a uniform gas of spin 1/2 atoms relaxing under superimposed fixed and rotating magnetic fields.