Nanoscale changes of the order parameter and current flow in HTSC thin films of YBCO and TBCCO

摘要

Nanoscale variation of the order parameter in superconductors can be generated by the presence of static and dynamic nano-structures or stripe-like features in HTSC. These nanoscale inhomogeneities would then affect the current flow. Electrical transport measurements happen to be the technique of choice to probe such nanoscale changes of the order parameter in the bulk of a superconductor. Passing a supercur-rent at the critical level through a sample ensures that the current flows through the entire volume of the sample, thus sensing its bulk properties. The electrical transport in YBCO and TBCCO thin films measured as a function of temperature and time supported the concept that the electrical properties of HTSC are governed by a mixture of two electronic phases: nanostructure and filamentary (stripe like) phases.