Spin and Conductance-Peak-Spacing Distributions in Large Quantum Dots: A Density Functional Theory Study

TL;DR

This study uses spin-density-functional theory to analyze conductance peak spacings and ground-state spins in large 2D quantum dots, revealing strong interaction effects and a high prevalence of high-spin states.

Contribution

It provides new insights into spin and conductance distributions in large quantum dots using advanced density functional theory methods.

Findings

Even/odd effect diminishes in large asymmetric dots

High-spin ground states are more common than previously thought

Interaction effects are stronger than expected in large quantum dots

Abstract

We use spin-density-functional theory to study the spacing between conductance peaks and the ground-state spin of 2D model quantum dots with up to 200 electrons. Distributions for different ranges of electron number are obtained in both symmetric and asymmetric potentials. The even/odd effect is pronounced for small symmetric dots but vanishes for large asymmetric ones, suggesting substantially stronger interaction effects than expected. The fraction of high-spin ground states is remarkably large.