Abstract: The ground state of a magnetopolaron that is weakly coupled with bulk longitudinal optical phonons and strongly coupled with interface optical phonons,in an infinite quantum well within magnetic fields is studied using the linear-combination operator and a modified LLP variational method.Rules for how the vibration frequency and self-trapping energy of the magnetopolaron change with the width of the quantum well and the magnetic fields are obtained.Our numerical results for a CdF2/AgCl QW show that the vibration frequency and the self-trapping energy of the magnetopolaron decrease with increasing well width and increase with increasing magnetic fields strength,but the contribution of interaction between the different branches of phonons and the electron and the magnetic fields to the vibration frequency and the self-trapping energy of the magnetopolaron are greatly different.The above-mentioned phenomena are also analyzed.

Key words: quantum well, magnetopolaron, vibration frequency, self-trapping energy