Observation of splintered Josephson vortices at grain boundaries in YBa2Cu3O7-δ -: art. no. 067004

We have directly observed well-separated Josephson vortex splinters with unquantized magnetic flux at asymmetric 45degrees grain boundaries in YBa2Cu3O7-delta films by imaging magnetic flux with scanning SQUID microscopy. The existence of these splinter vortices has been predicted and is well described by a model based on d(x)(2)-y(2) pairing symmetry and facetting of the grain boundary on a length scale shorter than the Josephson penetration depth.