Electronic structure of rectangular quantum dots

TL;DR

This paper investigates the electronic properties of rectangular quantum dots using advanced computational methods, revealing how shape deformation influences electron behavior, spin states, and charge density patterns.

Contribution

It provides new insights into how quantum dot geometry affects electronic structure, including spin-density waves and charge localization, using spin-density-functional theory and quantum Monte Carlo methods.

Findings

Electronic structure is highly sensitive to deformation.

Near degeneracy points, spin-density-wave solutions emerge.

Charge-density waves and localized states appear at large deformations.

Abstract

We study the ground state properties of rectangular quantum dots by using the spin-density-functional theory and quantum Monte Carlo methods. The dot geometry is determined by an infinite hard-wall potential to enable comparison to manufactured, rectangular-shaped quantum dots. We show that the electronic structure is very sensitive to the deformation, and at realistic sizes the non-interacting picture determines the general behavior. However, close to the degenerate points where Hund's rule applies, we find spin-density-wave-like solutions bracketing the partially polarized states. In the quasi-one-dimensional limit we find permanent charge-density waves, and at a sufficiently large deformation or low density, there are strongly localized stable states with a broken spin-symmetry.