Muon-spin rotation measurements of the vortex state in Sr${}_2$RuO${}_4$: type-1.5 superconductivity, vortex clustering and a crossover from a triangular to a square vortex lattice

S. J. Ray, A. S. Gibbs, S. J. Bending +5

Muon-spin rotation has been used to probe vortex state in Sr${}_2$RuO${}_4$. At moderate fields and temperatures a lattice of triangular symmetry is observed, crossing over to a lattic…