Impurity effect on the ground state binding energy of a fully coupled polaron in a double ring shaped quantum dot

Abstract

Double rings shaped quantum dot (DRSQD) is one of the important theoretical models for studying the properties of quantum dots (QD) in recent years, due to the superiority of its own double rings shaped potential (DRSP). Moreover, the influence of impurities on material properties is of great significance, because the presence of impurities can greatly affect the electro-optical properties of it. Ingeniously combining and exploring two methods of the Lee–Low–Pines unitary transformation (LLPUT) and linear combination operation (LCO) from both weak coupling limit (WCL) and strong coupling limit (SCL), the electrical properties of the fully coupled polaron (FCP) in DRSQD under the influence of impurities are indirectly considered. Under both the WCL and the SCL, the relational expressions of the polaron's vibrational frequency (VF), ground state energy (GSE) and ground state binding energy (GSBE) versus the parameters of the DRSP (PDRSP), the frequency of the DRSP (FDRSP) and the strength of the Coulomb's impurity potential (SCIP) are deduced, numerically calculated and analyzed. Besides, the contrast characteristics of the polaron's properties are given in the case of with or without impurity and under the WCL and the SCL. Simultaneously, we also compared the results of this paper with those of other literatures. The characteristic of the FCP in DRSQD under the influence of impurity effect is of great significance, because it provides new insights and references for the experimental design based on DRSQD.