Intermediate Low Spin States in a Few-electron Quantum Dot in the $\nu\le 1$ Regime

TL;DR

This paper investigates electron interactions in a few-electron quantum dot under strong magnetic fields, revealing ground state transitions and intermediate low-spin states beyond the maximum density droplet regime.

Contribution

It provides experimental excitation spectra and theoretical analysis showing the existence of intermediate low-spin states in the $ u\,\leq\,1$ regime, expanding understanding of quantum dot spin configurations.

Findings

Ground state transitions observed beyond $ u=1$

Intermediate low-spin states identified between spin-polarized states

Spectra match with exact diagonalization calculations

Abstract

We study the effects of electron-electron interactions in a circular few-electron vertical quantum dot in such a strong magnetic field that the filling factor $\nu\le 1$. We measure excitation spectra and find ground state transitions beyond the maximum density droplet ($\nu=1$) region. We compare the observed spectra with those calculated by exact diagonalization to identify the ground state quantum numbers, and find that intermediate low-spin states occur between adjacent spin-polarized magic number states.