Magnetic-field effects on exciton-polaron in a CdSe quantum disk

We study theoretically the interaction between excitons and longitudinal optical (LO) phonons in a cylindrical disk-like semiconductor quantum dot under an applied magnetic field. Due to the intensity of the interaction in the strong coupling regime, a composite quasi-particle called exciton-polaron is formed. We focus on the effect of the disk size and an external magnetic field on the exciton-phonon interaction energy and the exciton-polaron modes. The numerical computation for a CdSe quantum disk have shown that the exciton-phonon interaction energy is very significant and is even dominant when the disk height is small, which leads to a large Rabi splitting between the exciton-polaron modes. We investigate also the effect of the temperature on the integrated photoluminescence (PL) intensity, and show that at relatively high temperature the LO phonons have a noticeable effect on it. This physical parameter also shows a great dependence on quantum disk size and on magnetic field.