Roles of electron mean free path and flux pinning in optimizing the critical current in YBCO superconductors

Abstract

We present a way to reach the maximum possible critical current density, J(c), for YBa2Cu3O6+x (YBCO) thin films. This value is found to be around ten times the currently reached values. It is found that the J(c)(0 T) is governed by the mean free path of the electrons, as is the critical temperature, T-c. The J(c) in field, on the other hand, is governed by flux pinning sites and can be enhanced by optimizing the size and distribution of the non-superconducting nanoinclusions. By optimizing both the mean free path and the pinning structure, the maximum values can be reached.