Anomalous Phase Dynamics of Driven Graphene Josephson Junctions
Abstract
Josephson junctions with weak-links of exotic materials allow the elucidation of the Josephson effect in previously unexplored regimes. Further, such devices offer a direct probe of novel material properties, for example in the search for Majorana fermions. In this work, we report on DC and AC Josephson effect of high-mobility, hexagonal boron nitride (h-BN) encapsulated graphene Josephson junctions. On the application of RF radiation, we measure phase-locked Shapiro steps. An unexpected bistability between steps is observed with switching times on the order of seconds. A critical scaling of a bistable state is measured directly from the switching time, allowing for direct comparison to numerical simulations. We show such intermittent chaotic behavior is a consequence of the nonlinear dynamics of the junction and has a sensitive dependence on the current-phase relation. This work draws connections between nonlinear phenomena in dynamical systems and their implications for ongoing condensed matter experiments exploring topology and exotic physics.
Cite
@article{arxiv.1910.10125,
title = {Anomalous Phase Dynamics of Driven Graphene Josephson Junctions},
author = {S. S. Kalantre and F. Yu and M. T. Wei and K. Watanabe and T. Taniguchi and M. Hernandez-Rivera and F. Amet and J. R. Williams},
journal= {arXiv preprint arXiv:1910.10125},
year = {2020}
}