Magnetic-field modulated exciton-exciton interaction in semiconductor microcavities

We study the quantum-well magnetoexcitons by the variational method in the strong coupling regime of excitons with microcavity photons. In such strong coupling regime, we find that the coupling between the exciton internal state and center of mass motion can be neglected. Through the calculations, we find that the magnetic field can reduce the exciton exchange interaction to 30% as L_w =30 nm with L_w being the quantum well width. This is in contrast to the magnetic-field enhancement in the exciton Rabi splitting. In this work, we obtain that a magnetic field can enhance the exciton Rabi splitting up to 1.6 times in the case of L_w =30 nm. They both originate from the local enhancement in the exciton internal state due to the magnetic field. In addition, we analyze the behavior of the magnetic response of the exciton energy, Rabi splitting, and exchange interaction in manipulating the polariton parametric scattering, and widening the microcavity applications.