Polaron effect on low-lying energy spectrum of two electrons bound to a Coulomb impurity in a quantum dot

By using the exact numerical diagonalization scheme, we study the low-lying spectrum of a two-electron quantum dot with a confined parabolic potential in the presence of an on-center Coulomb impurity. The orbital angular mome ntum L and/or spin angular momentum S transitions induced by the magnetic f ield are reported. Furthermore, the effect of different electron-LO-phonon coupling strengths on the energy spectrum can be predicted.