Abstract
We report neutron scattering measurements of critical magnetic excitations in the weakly ferromagnetic superconductor UCoGe. The strong non-Landau damping of the excitations we observe, although unusual, has been found in another related ferromagnet, at zero pressure. However, we also find that there is a significant anisotropy of the magnetic correlation length in UCoGe that contrasts with an almost isotropic length for . The values of the magnetic correlation length and damping are found to be compatible with superconductivity on small Fermi-surface pockets. The anisotropy may be important to explain why UCoGe is a superconductor at zero pressure while is not.
- Received 27 July 2011
DOI:https://doi.org/10.1103/PhysRevLett.107.187202
© 2011 American Physical Society