Addition Spectra of Quantum Dots in Strong Magnetic Fields

TL;DR

This paper investigates how strong magnetic fields influence the chemical potential in quantum dots, revealing complex fine structures linked to many-body effects and fractional quantum Hall precursors.

Contribution

It introduces approximate expressions for magnetic field dependence in quantum dots that align with exact diagonalization results and highlights the importance of many-body effects.

Findings

Approximate models match exact diagonalization results.

Fine structure linked to ground-state level crossings.

Precursor features of fractional quantum Hall states identified.

Abstract

We consider the magnetic field dependence of the chemical potential for parabolically confined quantum dots in a strong magnetic field. Approximate expressions based on the notion that the size of a dot is determined by a competition between confinement and interaction energies are shown to be consistent with exact diagonalization studies for small quantum dots. Fine structure is present in the magnetic field dependence which cannot be explained without a full many-body description and is associated with ground-state level crossings as a function of confinement strength or Zeeman interaction strength. Some of this fine structure is associated with precursors of the bulk incompressible states responsible for the fractional quantum Hall effect.