ENERGY OF A BOUND POLARON IN A MAGNETIC-FIELD IN ASYMMETRIC POLAR SEMICONDUCTOR HETEROSTRUCTURES

In this paper, a new modified Hamiltonian of a polaron bound to a dono r impurity in asymmetric step quantum wells (QWs) in the presence of a n arbitrary magnetic held is given, in which the coupling of an electr on with confined bulk-like LO phonons, half-space LO phonons and inter face phonon modes is included. Especially, the interaction of the impu rity with all possible optical-phonon modes is also considered. The io nization energy of a bound polaron in a magnetic field for asymmetric step QWs are studied by using a modified Lee-Low-Pines (LLP) variation al method. The effects of the finite electronic confinement potential and the subband nonparabolicity are also considered. The relative impo rtance of the donor impurity located at the well and the step is analy zed. Our results show the interaction between the impurity and the pho non field in screening the Coulomb interaction has a significant influ ence on the binding energy of bound polaron. The influence of subband nonparabolicity is appreciable on the bound polaron effects for the na rrow well. The binding energy of bound polaron given in this paper are excellent agreement with the experimental measurement.