Electron bubbles in highly excited states of the lowest Landau level

TL;DR

This paper investigates the energy spectrum of electrons in the lowest Landau level, revealing highly excited states with electron bubbles and ordered structures, consistent across different interactions, and discusses their experimental realization.

Contribution

It uncovers highly excited electron bubble states with ordered structures in the lowest Landau level, a novel finding in quantum Hall physics.

Findings

Discovery of electron bubble states with local filling ν=1

Existence of these states for Coulomb and dipole interactions

Potential for experimental observation in moiré materials

Abstract

We study the entire energy spectrum of an electron droplet in the lowest Landau level. By exact diagonalization calculations, we find highly excited states in the middle of the spectrum that display unexpected density distribution and pair correlation. We show that these exceptional excited states contain tightly bound electron bubbles with local filling $\nu = 1$ that form various ordered structures. Remarkably, these bubble excited states are shown to exist for both the $1/r$ Coulomb interaction and the $1/r^3$ dipole interaction. The experimental realization of bubble excited states in moir\'e materials under a magnetic field is also discussed.