Geometric Suppression of Single-Particle Energy Spacings in Quantum Antidots

TL;DR

This paper explains the suppression of energy spacings in quantum antidots through a geometric model, avoiding the need for electron interaction effects, which aids in designing quantum devices.

Contribution

The study combines experimental data with new calculations to show how potential geometry alone accounts for energy suppression in quantum antidots, challenging interaction-based explanations.

Findings

Suppression of energy spacings explained by potential geometry

No need to invoke electron interactions for observed effects

Insights useful for quantum device design

Abstract

Quantum Antidot (AD) structures have remarkable properties in the integer quantum Hall regime, exhibiting Coulomb-blockade charging and the Kondo effect despite their open geometry. In some regimes a simple single-particle (SP) model suffices to describe experimental observations while in others interaction effects are clearly important, although exactly how and why interactions emerge is unclear. We present a combination of experimental data and the results of new calculations concerning SP orbital states which show how the observed suppression of the energy spacing between states can be explained through a full consideration of the AD potential, without requiring any effects due to electron interactions such as the formation of compressible regions composed of multiple states, which may occur at higher magnetic fields. A full understanding of the regimes in which these effects occur is important for the design of devices to coherently manipulate electrons in edge states using AD resonances.