The magnetic multi-k form factor: an experimental signature of quantum   correlators in USb0.88Te0.12?
  Magnetic diffraction patterns which exhibit more than one discrete set of symmetry related peaks have been explained by the simultaneous coexistence of more than one magnetic polarisation and propagation vector, k, in the scattering amplitude. In this work we suggest using such multi-k magnetic structures as prototypical multiple order parameter systems. The examples studied are uranium rocksalts, which exhibit magnetic diffraction patterns, the indexing of which requires three orthogonal propagation wavevectors. In the cubic phase these systems exhibit, in addition to the three sets of symmetry related magnetic diffraction peaks, a set of additional Bragg peaks which have been observed by both neutron and x-ray resonant scattering. An interpretation of the neutron diffraction form factor of these peaks is presented, identifying these peaks as signatures of quantum coherence between the three orthogonal order parameters. 
E. Blackburn and N. Bernhoeft