Influence of Magnetic Field on Bound Polarons in Semiconductor GaAs/AlxGa1-xAs Heterojunctions
磁场对GaAs/Al_xGa_(1-x)As异质结系统中束缚极化子的影响

A modified LLP variational method is adopted to investigate the binding energies of bound polarons near the interface of single heterojunction system of semiconductor in the presence of static uniform magnetic field by using a triangular potential approximate to the interface potential.The influences of the electron-phonon and impurity-phonon interaction including the effect of half-space bulk longitudinal and interface-optical phonon modes are considered.The computation is performed for GaAs/Al xGa 1-xAs structure.The relations among the impurity binding energies and the impurity position,magnetic field strength,the electron areal density are calculated,respectively.It is found that binding energy of the bound polaron shows a monotonic increase tendency with increasing the magnetic field strength B.The contribution from bulk longitudinal optical phonons to the binding energy obviously increases with increasing B,but the interface optical phonons are insensitive to magnetic field except for the impurity being near the interface.It also shows that the conductive band bending can not be neglected.Furthermore,the influence of the electron image potential is negligibly small so that it can be neglected in the further discussion.