SU(4) Skyrmions in the $\nu=\pm 1$ Quantum Hall State of Graphene

TL;DR

This paper investigates various SU(4) skyrmion types in graphene's quantum Hall state at filling factor ±1, highlighting the emergence of spin, valley pseudospin, and entangled skyrmions influenced by symmetry-breaking effects.

Contribution

It reveals the stabilization of spin-valley entangled skyrmions in graphene due to approximate SU(4) symmetry and analyzes their signatures in density measurements.

Findings

Identification of spin, valley pseudospin, and entangled skyrmions in graphene.

Prediction of distinct density patterns for different skyrmion types.

Demonstration of symmetry-breaking effects on skyrmion stability.

Abstract

We explore different skyrmion types in the lowest Landau level of graphene at a filling factor $\nu=\pm 1$. In addition to the formation of spin and valley pseudospin skyrmions, we show that another type of spin-valley entangled skyrmions can be stabilized in graphene due to an approximate SU(4) spin-valley symmetry that is affected by sublattice symmetry-breaking terms. These skyrmions have a clear signature in spin-resolved density measurements on the lattice scale, and we discuss the expected patterns for the different skyrmion types.