Boosting Transparency in Topological Josephson Junctions via Stencil Lithography

• Main Authors: Schüffelgen, Peter, Rosenbach, Daniel, Li, Chuan, Schmitt, Tobias, Schleenvoigt, Michael, Jalil, Abdur R, Kölzer, Jonas, Wang, Meng, Bennemann, Benjamin, Parlak, Umut, Kibkalo, Lidia, Luysberg, Martina, Mussler, Gregor, Golubov, Alexander. A, Brinkman, Alexander, Schäpers, Thomas, Grützmacher, Detlev
• Format: Journal Article
• Language: English
• Published: 05-11-2017
• Subjects: Physics - Superconductivity
• DOI: 10.48550/arxiv.1711.01665

Hybrid devices comprised of topological insulator (TI) nanostructures in
proximity to s-wave superconductors (SC) are expected to pave the way towards
topological quantum computation. Fabrication under ultra-high vacuum conditions
is necessary to attain high quality of TI-SC hybrid devices, because the
physical surfaces of V-VI three-dimensional TIs suffer from degradation at
ambient conditions. Here, we present an in-situ process, which allows to
fabricate such hybrids by combining molecular beam epitaxy and stencil
lithography. As-prepared Josephson junctions show nearly perfect interface
transparency and very large $I_CR_N$ products. The Shapiro response of radio
frequency measurements indicates the presence of gapless Andreev bound states,
so-called Majorana bound states.