Linear excitonic absorption under an external electric field in quantum dot molecules

Abstract

A study of the excitonic states in artificial molecules set up of two vertically coupled double quantum dots is presented. The electron and hole eigenstates are calculated for the quantum dot molecule. In particular, the coupling effect of the barrier and the consequent tunneling is analyzed following the evolution of the absorption spectra as function of the distance between the two dots. On the other hand, the role of the Coulomb correlation between the confined particles is also studied. We present results of relevant interactions in these systems and discuss how the optical properties of double quantum dots are affected by the interdot coupling, by the geometry of the dots and by an applied electric field.

Excitonic States and Photoluminescence Spectra of a Quantum Dot Molecule Exposed to the External Static Electric Field

“…For completeness, the oscillator strength calculated using formula (13) is presented in Figure 7a. One can see that the far-field oscillator strengths and, consequently, absorption spectra significantly differ from the luminescence spectra.…”

“…The energies of excitonic states and photoluminescence (PL) intensities connected with discrete levels are changed as the applied electric field modifies the shape of the confinement potential both for an electron and a hole. The tunneling of charged particles, excitonic absorption and PL intensity, exchange interaction] can be controlled by external bias voltage.…”