With the advance in the nanofabrication technology

there has been a great deal of interest in the investigation of quasi-zero-dimensional electronic systems(quantum dots).Because of the wide device applications and a lot of new physical effects in such structures

understanding the electronic properties of these systems is of particular importance.Several studies have already been carried out on the interaction of the electrons with longitudinal-optical(LO) phonons in quantum dots.Recently

Zhu and Kobayashi used the Landau-Pekar variational treatment to study the strong coupling polaron binding energy of the ground state and the average number of virtual phonons around the electron in quantum dots in the presence of magnetic fields.Taking into account the electron-bulk LO-phonon interaction

Kandemir and Altanhan used the Lee-Low-Pines transformation to calculate the polaronic effects for an electron confined in a parabolic quantum dot in a uniform magnetic field.Zhu and Gu investigated the polaronic states in a parabolic quantum dot by using the second order Rayleigh-Schrodinger perturbation theory.It is shown that the absolute values of the ground state energy correction and the excited state energy correction as well as the relevant transition energies increase with decreasing the size of the quantum dot.The results also indicate that the polaron effects in small quantum dots are stronger than those in the corresponding bulk materials.In the papers of Zhou and Gu

by using the variational method of Pekar type

the ground state and the first excited state of the strong coupling magnetopolaron in cylinder-shape and disk-shape quantum dot were considered.The results show that

with the increasing cyclotron frequency and the confinement strength

the magnetopolaron binding energies in both the ground state and the excited state

and the resonance frequency of magnetopolaron are enhanced.However

the properties of magnetopolaron in the excited state in parabolic quantum dot has not been studied so far.In this paper

by using the variational method of Pekar type

both the ground state and the excited state of strong coupling magnetopo-laron in parabolic quantum dot were studied.The magnetopolaron binding energies in both the ground state and the excited state

and the resonance frequency of magnetopolaron were calculated.Their dependence on the cyclotron frequency and the confinement strength was depicted.