Observation of nonsinusoidal current-phase relation in graphene Josephson junctions

C. D. English, D. R. Hamilton, C. Chialvo, I. C. Moraru, N. Mason, D. J. Van Harlingen
2016 Physical review B  
The current-phase relation of a Josephson junction can reveal valuable information about the processes influencing the supercurrent. In this Letter, we present direct measurements of the current phase relation for Josephson junctions having a graphene barrier, obtained by a phase-sensitive SQUID interferometry technique. We find that the current phase relation is forward skewed with respect to the commonly observed sinusoidal behavior for short junctions in the quasi-ballistic transport regime,
more » ... c transport regime, consistent with predictions for the behavior of Dirac fermions in a Josephson junction. The skewness increases with critical current and decreases sharply with increasing temperature.
doi:10.1103/physrevb.94.115435 fatcat:4f5qncd6bvgyzflxfad4yblhyu