Critical Current 0-$π$ Transition in Designed Josephson Quantum Dot Junctions

Jørgensen, H. Ingerslev; Novotný, T.; Grove-Rasmussen, K.; Flensberg, K.; Lindelof, P. E.

Critical Current 0-$π$ Transition in Designed Josephson Quantum Dot Junctions

Authors

Jørgensen, H. Ingerslev

Description

We report on quantum dot based Josephson junctions designed specifically for measuring the supercurrent. From high-accuracy fitting of the current-voltage characteristics we determine the full magnitude of the supercurrent (critical current). Strong gate modulation of the critical current is observed through several consecutive Coulomb blockade oscillations. The critical current crosses zero close to, but not at, resonance due to the so-called 0-$π$ transition in agreement with a simple theoretical model.
5 pages, 4 figures, (Supplementary information available at http://www.fys.ku.dk/~hij/public/nl_supp.pdf)