Superconducting heterostructures interlayered with a material with strong spin–orbit interaction

Superconducting heterostructures interlayered with a material with strong spin–orbit interaction are studied. As materials with strong spin–orbit interaction, we choose strontium iridates featuring the Ruddlesden–Popper structure (Sr$_{n+1}$Ir$_{n}$O$_{3n+1}$; $n$ = 1, 2, $\infty$): paramagnetic metal SrIrO$_3$ and magnetic insulator Sr$_2$IrO$_4$. Using laser ablation, epitaxial films of these materials are obtained, as well as heterostructures based on epitaxial films of cuprate superconducting YBa$_{2}$Cu$_{3}$O$_{x}$. For electrical measurements, mesa-structures of micrometer sizes with top electrodes made of Au/Nb bilayer are fabricated.