Topological insulator nanoribbon Josephson junctions: Evidence for size effects in transport properties
Journal article, 2020
We have used Bi 2 Se 3 nanoribbons, grown by catalyst-free physical vapor deposition to fabricate high quality Josephson junctions with Al superconducting electrodes. In our devices, we observe a pronounced reduction of the Josephson critical current density J c by reducing the width of the junction, which in our case corresponds to the width of the nanoribbon. Because the topological surface states extend over the entire circumference of the nanoribbon, the superconducting transport associated with them is carried by modes on both the top and bottom surfaces of the nanoribbon. We show that the J c reduction as a function of the nanoribbon width can be accounted for by assuming that only the modes traveling on the top surface contribute to the Josephson transport as we derive by geometrical consideration. This finding is of great relevance for topological quantum circuitry schemes since it indicates that the Josephson current is mainly carried by the topological surface states.
Author
Gunta Kunakova
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
University of Latvia
Ananthu Pullukattuthara Surendran
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Domenico Montemurro
University of Naples Federico II
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Matteo Salvato
University of Rome Tor Vergata
Dmitry Golubev
Aalto University
J. Andzane
University of Latvia
Donats Érts
University of Latvia
Thilo Bauch
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Floriana Lombardi
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Journal of Applied Physics
0021-8979 (ISSN) 1089-7550 (eISSN)
Vol. 128 19 194304Subject Categories
Other Physics Topics
Fusion, Plasma and Space Physics
Condensed Matter Physics
DOI
10.1063/5.0022126