Spin-density-functional theory of circular and elliptical quantum dots

TL;DR

This paper employs spin-density-functional theory to analyze electronic states in 2D quantum dots, revealing shell structures, spin configurations, and the effects of potential deformation on charge-density waves.

Contribution

It provides new insights into the ground state properties and the limitations of spin-density-functional theory in describing spin states in quantum dots.

Findings

Shell structure observed in electron filling

Hund's rule applies up to 22 electrons

Deformation induces charge-density-wave states

Abstract

Using spin-density-functional theory, we study the electronic states of a two-dimensional parabolic quantum dot with up to N=58 electrons. We observe a shell structure for the filling of the dot with electrons. Hund's rule determines the spin configuration of the ground state, but only up to 22 electrons. At specific N, the ground state is degenerate, and a small elliptical deformation of the external potential induces a rotational charge-density-wave (CDW) state. Previously identified spin-density-wave (SDW) states are shown to be artifacts of broken spin symmetry in density-functional theory.