Singular states of relativistic fermions in the field of a circularly   polarized electromagnetic wave and constant magnetic field
  Dirac's equation in the field of a circularly polarized electromagnetic wave and constant magnetic field has exact localized non-stationary solutions. The solutions corresponds relativistic fermions only. Among them singular solutions with energy eigenvalues close to each other are found. The solutions are most practicable and can be separated by means of the phase matching between the momentum of the electromagnetic wave and spinor. Characteristic parameters of the singular states are defined. 
Boris V. Gisin
physics.gen-ph