Muons as Local Probes of Three-body Correlations in the Mixed State of   Type-II Superconductors
  The vortex glass state formed by magnetic flux lines in a type-II superconductor is shown to possess non-trivial three-body correlations. While such correlations are usually difficult to measure in glassy systems, the magnetic fields associated with the flux vortices allow us to probe these via muon-spin rotation measurements of the local field distribution. We show via numerical simulations and analytic calculations that these observations provide detailed microscopic insight into the local order of the vortex glass and more generally validate a theoretical framework for correlations in glassy systems. 
G. I. Menon, A. Drew, U.K. Divakar, S.L. Lee, R. Gilardi, J. Mesot,   F.Y. Ogrin, D. Charalambous, E.M. Forgan, N. Momono, M...