Magnetic effect on dynamic and decoherence of exciton polaron in transition metal dichalcogenides

Abstract

We investigate the dynamics and decoherence of the exciton polaron in a 2D transition metal dichalcogenides modulated by a magnetic field barrier. Using the Huybrechts method and an approximate diagonalization of exciton-phonon operators is performed to derive the fundamental energy, the first excited state energy, the effective mass and the mobility of the exciton polaron. It is found that the system presents robust state energies and the dynamic properties like effective mass is reduced. We show that the motion of exciton-polaron is accelerated by increasing the magnetic barrier length. The transition of the exciton polaron from the valence band to the conduction band is also enhanced by the external field. It is found that the decoherence of exciton polaron can be adjusted by the magnetic field barrier. Our results suggest that the magnetic field barrier (i) enhances the confinement of the electron in the system, (ii) increases mobility and the rate of the decoherence of exciton polaron. The results are in agreement with experimental works.