Electronic structure of quantum dots

TLDR

Quasi‑two‑dimensional semiconductor quantum dots exhibit rich electronic properties, including shell structure, spontaneous magnetization from Hund’s rule, spin‑density waves, and electron localization. The study investigates the formation of the maximum‑density droplet and its edge reconstruction in finite quantum dots under strong magnetic fields. Experimental measurements of electronic shell structure and magnetic‑field effects, combined with single‑particle, density‑functional, and exact‑diagonalization models, are applied to quantum dots, rings, deformed dots, and dot molecules to analyze maximum‑density droplet behavior. The electronic structure of quantum dots transitions through multiple distinct phases as the magnetic field varies.

Abstract

The properties of quasi-two-dimensional semiconductor quantum dots are reviewed. Experimental techniques for measuring the electronic shell structure and the effect of magnetic fields are briefly described. The electronic structure is analyzed in terms of simple single-particle models, density-functional theory, and ``exact'' diagonalization methods. The spontaneous magnetization due to Hund's rule, spin-density wave states, and electron localization are addressed. As a function of the magnetic field, the electronic structure goes through several phases with qualitatively different properties. The formation of the so-called maximum-density droplet and its edge reconstruction is discussed, and the regime of strong magnetic fields in finite dot is examined. In addition, quasi-one-dimensional rings, deformed dots, and dot molecules are considered.