Far-infrared spectra of lateral quantum dot molecules

TL;DR

This paper investigates how electron interactions and confinement shape the far-infrared spectra of lateral quantum dot molecules, revealing that spectra are sensitive to potential symmetry and electron number.

Contribution

It provides detailed calculations of FIR spectra for various quantum dot potentials and electron counts using exact diagonalization and perturbation theory.

Findings

FIR spectra reflect the symmetry of the confinement potential.

Interactions cause only small shifts in the spectra.

Additional spectral features emerge with more electrons.

Abstract

We study effects of electron-electron interactions and confinement potential on the magneto-optical absorption spectrum in the far-infrared range of lateral quantum dot molecules. We calculate far-infrared (FIR) spectra for three different quantum dot molecule confinement potentials. We use accurate exact diagonalization technique for two interacting electrons and calculate dipole-transitions between two-body levels with perturbation theory. We conclude that the two-electron FIR spectra directly reflect the symmetry of the confinement potential and interactions cause only small shifts in the spectra. These predictions could be tested in experiments with nonparabolic quantum dots by changing the number of confined electrons. We also calculate FIR spectra for up to six noninteracting electrons and observe some additional features in the spectrum.