Observation of vortex coalescence in the anisotropic spin-triplet   superconductor Sr$_{2}$RuO$_{4}$
  We present direct imaging of magnetic flux structures in the anisotropic, spin-triplet superconductor Sr$_{2}$RuO$_{4}$ using a scanning $\mu$SQUID microscope. Individual quantized vortices were seen at low magnetic fields. Coalescing vortices forming flux domains were revealed at intermediate fields. Based on our observations we suggest that a mechanism intrinsic to the material stabilizes the flux domains against the repulsive vortex-vortex interaction. Topological defects like domain walls can provide this, implying proof for unconventional chiral superconductivity. 
V. O. Dolocan, C. Veauvy, Y. Liu, F. Servant, P. Lejay, D. Mailly, K.   Hasselbach