We theoretically examine the effect of the magnetic field on the relaxation process of the exciton-polariton toward the Bose-Einstein condensation in GaAs quantum wells. As a result of the modification of the exciton's effective mass, Rabi splitting, and dispersion, the relaxation rate of polaritons toward condensation has been significantly modified. Using a continuous pumping, the dynamics of total and condensated polariton versus magnetic field has been clarified. It has been shown that for low-energy pumping, the condensation is significantly reduced with a magnetic field, and this arises from the reduction of the scattering rate between energy levels when the steepness of the dispersion at higher energy is reduced. Increasing of pump energy together with the magnetic field could lead to a more effective relaxation and a much higher number of condensated polariton is obtained.
Comment: 13 page, 5 figures