Proximity-Induced Superconductivity and Quantum Interference in Topological Crystalline Insulator SnTe Thin-Film Devices

• Published in: Nano letters Vol. 18; no. 2; pp. 1264 - 1268
• Main Authors: Klett, Robin, Schönle, Joachim, Becker, Andreas, Dyck, Denis, Borisov, Kiril, Rott, Karsten, Ramermann, Daniela, Büker, Björn, Haskenhoff, Jan, Krieft, Jan, Hübner, Torsten, Reimer, Oliver, Shekhar, Chandra, Schmalhorst, Jan-Michael, Hütten, Andreas, Felser, Claudia, Wernsdorfer, Wolfgang, Reiss, Günter
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 14.02.2018
• Subjects: Physics; Thin films; topological insulator; superconductivity; mesoscopic devices
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.7b04870

Topological crystalline insulators represent a new state of matter, in which the electronic transport is governed by mirror-symmetry protected Dirac surface states. Due to the helical spin-polarization of these surface states, the proximity of topological crystalline matter to a nearby superconductor is predicted to induce unconventional superconductivity and, thus, to host Majorana physics. We report on the preparation and characterization of Nb-based superconducting quantum interference devices patterned on top of topological crystalline insulator SnTe thin films. The SnTe films show weak anti-localization, and the weak links of the superconducting quantum interference devices (SQUID) exhibit fully gapped proximity-induced superconductivity. Both properties give a coinciding coherence length of 120 nm. The SQUID oscillations induced by a magnetic field show 2π periodicity, possibly dominated by the bulk conductivity.