NMR Evidence for Spin-Pseudospin Intermixing in Quantum Hall Skyrmions

TL;DR

This study uses NMR techniques to reveal that in bilayer quantum Hall systems near filling factor 1, quasiparticles exhibit a continuous increase in spin and pseudospin components, indicating the presence of spin-pseudospin intermixed SU(4) skyrmions.

Contribution

It provides experimental evidence for spin-pseudospin intermixing in quantum Hall skyrmions, demonstrating the existence of SU(4) skyrmions with combined spin and pseudospin characteristics.

Findings

Spin component increases with $ ext{Δ}_{SAS}$

Both spin and pseudospin are contained in quasiparticles at intermediate $ ext{Δ}_{SAS}$

Collective behavior of skyrmions changes with $ ext{Δ}_{SAS}$

Abstract

We investigate quasiparticles in bilayer quantum Hall systems around total filling factor nu =1 by current-pumped and resistively detected NMR. The measured Knight shift reveals that the spin component in the quasiparticle increases continuously with $\Delta_{SAS}$. Combined with results for the pseudospin component obtained by activation gap measurements, this demonstrates that both spin and pseudospin are contained in a quasiparticle at intermediate $\Delta_{SAS}$, providing evidence for the existence of the spin-pseudospin intermixed SU(4) skyrmion. Nuclear spin relaxation measurements show that the collective behavior of the SU(4) skyrmion system qualitatively changes with $\Delta_{SAS}$.