Spin Polarizations at and about the Lowest Filled Landau Level

TL;DR

This study investigates spin polarization behavior near the lowest Landau level, demonstrating agreement with experiments and providing evidence for skyrmionic excitations at filling factor one.

Contribution

It offers the first detailed analysis of spin polarization at ν=1 including finite-thickness effects and confirms skyrmions as the fundamental excitations.

Findings

Results agree with experimental data at ν=1.

Skyrmions with topological charge Q ≥ 2 are confirmed.

Q=1 excitations are single spin-flip states.

Abstract

The spin polarization versus temperature at or near a fully filled lowest Landau level is explored for finite-size systems in a periodic rectangular geometry. Our results at $\nu=1$ which also include the finite-thickness correction are in good agreement with the experimental results. We also find that the interacting electron system results are in complete agreement with the results of the sigma model, i.e., skyrmions on a torus have a topological charge of $Q \ge 2$ and the Q=1 solution is like a single spin-flip excitation. Our results therefore provide direct evidence for the skyrmionic nature of the excitations at this filling factor.