Year: 2023
Type: preprint
Abstract: Superconducting electrodes are an integral part of hybrid Josephson junctions used in many applications including quantum technologies. We report on the fabrication and characterization of superconducting hybrid Au/YBa2Cu3O7-x (YBCO) electrodes on vicinal substrates. In these structures, superconducting CuO2-planes face the gold film, resulting in a higher value and smaller variation of the induced energy gap compared to the conventional Au/YBCO electrodes based on films with the c-axis normal to the substrate surface. Using scanning tunneling microscopy, we observe an energy gap of about 10-17 meV at the surface of the 15- nm-thick gold layer deposited in situ atop the YBCO film. To study the origin of this gap, we fabricate nanoconstrictions from the Au/YBCO heterostructure and measure their electrical transport characteristics. The conductance of the nanoconstrictions shows a series of dips due to multiple Andreev reflections in YBCO and gold providing clear evidence of the superconducting nature of the gap in gold. We consider the Au/YBCO electrodes to be a versatile platform for hybrid Josephson devices with a high operating temperature.
Source: arXiv (Cornell University)
Authors: Gundareva, Irina, Martinez-Castro, Jose, Tautz, Frank Stefan, Mussler, Gregor, Jalil, Abdur Rehman, Hou, Xiao, Grützmacher, Detlev, Schäpers, Thomas, Lyatti, Matvey
Institution: RWTH Aachen University
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4387076337