Collective charge-density excitations of non-circular quantum dots in a magnetic field

TL;DR

This paper uses computational methods to analyze charge-density excitations in non-circular quantum dots under magnetic fields, revealing how symmetry breaking improves agreement with experimental observations.

Contribution

It introduces a systematic computational approach to study non-circular quantum dots' excitations, highlighting the impact of symmetry breaking on their spectral features.

Findings

Symmetry breaking leads to new spectral features.

Electronic shell structure explains main experimental characteristics.

Computational results align with photoabsorption measurements.

Abstract

Recent photoabsorption measurements have revealed a rich fine structure in the collective charge-density excitation spectrum of few-electron quantum dots in the presence of magnetic fields. We have performed systematic computational studies of the far-infrared density response of quantum dots, using time-dependent density-functional theory in the linear regime and treating the dots as two-dimensional disks. It turns out that the main characteristics observed in the experiment can be understood in terms of the electronic shell structure of the quantum dots. However, new features arise if a breaking of the circular symmetry of the dots is allowed, leading to an improved description of the experimental results.