量子点中磁激子的极化子效应

采用推广的LLP方法研究了自组织量子点中磁激子的极化子效应。考虑带电粒子和声子的相互作用,得到了激子能量随磁场的变化关系。结果表明,激子-声子的相互作用降低了激子的能量,但影响很小;极化子效应在没有外磁场时较明显,随着外磁场的增加,这种效应变得越来越弱。

Polaron Effects on Magneto-exciton in Quantum Dots

A quantum dot(QD) consists of an artificial structure in which electrons are confined in all three spatial dimensions and thus has a fully quantized energy spectrum.A set of electrons held in such a structure is similar to a set of atomic electrons bound to a nucleus,and for this reason QDs are sometimes termed "artificial atoms".Optical and electric properties of QDs structures recently have attracted much attention because of their application potential.These properties are closely related to excitonic states and their coupling with optical phonon modes.There has been a considerable amount of work on the properties of excitons in different QD structures experimentally and theoreti-cally.The purpose of the present work is to investigate the polaron effects on the magneto-exciton in assembled QDs,and to describe a calculation of the Coulomb interaction with a simple perturbation theory.It was shown that,the interaction of the charged particles with bulk longitudinal optical phonons(LO-phonons) is primary and first important.So in this work we restrict ourselves to examine the interaction of electron and hole with bulk LO-phonons only.We write down the Hamiltonian of the exciton-phonon system in QDs with an external magnetic field,and obtain the energy levels of the system by using a developed LLP method.The results show that the polaron effects on the magneto-exciton are to lower the energy levels,but the decrements are small.