Few-electron molecular states and their transitions in a single InAs quantum dot molecule

TL;DR

This paper investigates the electronic configurations and magnetic field-induced transitions in a single InAs quantum dot molecule with few electrons, combining experimental transport data and many-body calculations to identify molecular states.

Contribution

It provides the first detailed comparison of experimental spectra with theoretical models for few-electron InAs quantum dot molecules, revealing magnetic field effects on state filling.

Findings

Identification of spin and orbital configurations in quantum dot molecules

Observation of magnetic field-induced transitions in molecular states

Confirmation of symmetric and anti-symmetric state filling behaviors

Abstract

We study electronic configurations in a single pair of vertically coupled self-assembled InAs quantum dots, holding just a few electrons. By comparing the experimental data of non-linear single-electron transport spectra in a magnetic field with many-body calculations, we identify the spin and orbital configurations to confirm the formation of molecular states by filling both the quantum mechanically coupled symmetric and anti-symmetric states. Filling of the anti-symmetric states is less favored with increasing magnetic field, and this leads to various magnetic field induced transitions in the molecular states.