A theoretical study of exciton energy levels in laterally coupled quantum dots

Abstract

A theoretical study of the electronic and optical properties of laterally coupled quantumdots, under applied magnetic fields perpendicular to the plane of the dots, is presented.The exciton energy levels of such laterally coupled quantum-dot systems, together with thecorresponding wavefunctions and eigenvalues, are obtained in the effective-massapproximation by using an extended variational approach in which the magnetoexcitonstates are simultaneously obtained. One achieves the expected limits of one single quantumdot, when the distance between the dots is zero, and of two uncoupled quantum dots, whenthe distance between the dots is large enough. Moreover, present calculations—withappropriate structural dimensions of the two-dot system—are shown to be in agreementwith measurements in self-assembled laterally aligned GaAs quantum-dot pairs andnaturally/accidentally occurring coupled quantum dots in GaAs/GaAlAs quantumwells.