Influence of magnetic field and Rashba spin-orbit coupling on strong-coupling magnetopolarons in quantum disks

On the basis of Lee-Low-Pines (LLP) unitary transformation, the influence of external magnetic field, Rashba spin-orbit coupling and quantum size effect on the ground-state interaction energy of strong-coupling magnetopolarons in quantum disks (QDs) is studied by using the Tokuda improved linear combine operator method. The results show that the ground-state interaction energy of magnetopolarons consists of four parts: the energy caused by the confinement potential of QDs, interaction energy between the electron and external magnetic field, electron and longitudinal-optical (LO) phonon interaction energy and additional term of Rashba effect originating from phonons. The electron-LO phonon interaction energy Ee-ph and additional term of Rashba effect are always negative; the absolute value |Ee-ph| increases with increasing transverse confinement strength omega(0), cyclotron frequency of external magnetic field omega(c) and electron-LO phonon coupling strength omega(0), but decreases with increasing the thickness of QDs L; the state properties of magnetopolarons are closely linked with the sign of the ground-state interaction energy of magnetopolarons E-int and change of E-int with omega(c), omega(0), alpha and L. In addition, the vibration frequency of magnetopolarons lambda increases with increasing omega(c), omega(0) and alpha, but decreases with increasing L. For the ground state of magnetopolarons in QDs, the electron-LO phonon interaction plays a significant role, meanwhile, the influence of Rashba spin-orbit coupling effect cannot be ignored.