Influence of disorder on the vortex pinning and cutting of YBa$_2$Cu$_3$O$_7$ films

Flux cutting and recombination has been used to explain high critical current densities ($J_c$) observed in experiments done in Force-Free (FF) and Variable Lorentz Force(VLF) configurations \textit{i.e.}, when the current $I$ is totally or partially aligned to the applied magnetic field $H$. However, the effect of different pinning centers has not been studied. We present angular and field $J_c$ studies in FF and VLF configurations and study the effects of random, correlated and extended defects on the $J_c$ of YBa$_2$Cu$_3$O$_7$ films. Results are analyzed in terms of vortex pinning at different defects and vortex cutting mechanism. We show that pinning greatly influences $J_c$ in FF and VLF, up to the point of obtaining $J_c$ higher than $J_c(H=0) $ up to magnetic fields as high as 3T