Excitations in antiferromagnetic cores of superconducting vortices

TL;DR

This paper investigates excitations in antiferromagnetic vortex cores within a superconducting SO(5) model, predicting possible enhanced neutron scattering signals and bound or Goldstone modes depending on symmetry conditions.

Contribution

It provides a theoretical analysis of vortex core excitations in the SO(5) model, highlighting effects of symmetry breaking on observable modes.

Findings

Potential for enhanced neutron scattering near 41 meV

Existence of bound excitations below 41 meV in vortex cores

Massive Goldstone modes around 2 meV due to symmetry breaking

Abstract

We study excitations of the predicted antiferromagnetically ordered vortex cores in the superconducting phase of the newly proposed SO(5) model of strongly correlated electrons. Using experimental data from the literature we show that the susceptibilities in the spin sector and the charge sector are nearly equal, and likewise for the stiffnesses. In the case of strict equality SO(5) symmetry is possible, and we find that if present the vortices give rise to an enhanced neutron scattering cross section near the so called pi resonance at 41 meV. In the case of broken SO(5) symmetry two effects are predicted. Bound excitations can exist in the vortex cores with ``high'' excitation energies slightly below 41 meV, and the massless Goldstone modes corresponding to the antiferromagnetic ordering of the core can acquire a mass and show up as core excitation with ``low'' excitation energies around 2 meV.