Properties of nanopatterned pins generated in a superconductor with FIB

We have used focused ion-beam to nanopattern an array of artificial pinning centers on the surface of a superconductor. By investigation of the bulk as well as local magnetization responses we find that the pinning properties of the artificially generated pins differ significantly from those in an unpatterned superconductor with natural pinning centers. The gradients in the magnetic field distribution inside the nanopatterned region have very different field dependences compared to those outside it. The non-equilibrated nature of the flux distribution due to artificial pins is associated with a magnetization response which is dependent on the rate at which magnetic field is swept during the measurements. The array of artificially generated pins produces large increases in pinning force at large drives and at high fields, which potentially could help in enhancing the current carrying capability of superconductors especially at high fields.