Higher Landau levels contribution to the energy of interacting electrons in a quantum dot

TL;DR

This paper uses regularized second-order perturbation theory to evaluate how higher Landau levels affect the energy spectrum of interacting electrons in quantum dots, revealing significant contributions near filling factor 1/2.

Contribution

It introduces a regularized perturbation approach to include higher Landau levels in quantum dot energy calculations, extending analysis to larger systems beyond exact diagonalization capabilities.

Findings

Higher Landau levels significantly influence energy near filling factor 1/2.

Method converges reliably in small systems and applied to 12-electron quantum dot.

Results show importance of higher Landau levels in quantum dot energy spectra.

Abstract

Properly regularized second-order degenerate perturbation theory is applied to compute the contribution of higher Landau levels to the low-energy spectrum of interacting electrons in a disk-shaped quantum dot. At ``filling factor'' near 1/2, this contribution proves to be larger than energy differences between states with different spin polarizations. After checking convergence of the method in small systems, we show results for a 12-electron quantum dot, a system which is hardly tractable by means of exact diagonalization techniques.