1. Transport at Nanoscale Interfaces Laboratory, Swiss Federal Laboratories for Material Science and Technology (EMPA), Ueberlandstrasse 129, 8600 Duebendorf, Switzerland
2. Texas Center for Superconductivity and Department of Physics, University of Houston, Houston, Texas 77204-5002, United States
3. Materials Science Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
4. Centre for Nano Fabrication and Characterization (DTU Nanolab), Technical University of Denmark, 2800 Kongens Lyngby, Denmark