We investigate the current-phase-relation (CPR) of long diffusive superconductor-normal metal-superconductor (SNS) Josephson junctions in thermodynamic equilibrium and under microwave irradiation. While in equilibrium good agreement with the predictions of quasi-classical theory is found, we observe that the shape of the CPR can be strongly affected by microwave irradiation. Close to a Josephson-phase difference of pi, the supercurrent can be strongly suppressed when increasing the rf-power. Our results can be understood in terms of microwave excitation of low-lying Andreev bound states across the mini-gap in the junction. In the frequency interval studied, this mechanism becomes important when the mini-gap closes at a phase difference of pi.
@article{arxiv.0707.4512,
title = {Effect of Microwaves on the Current-Phase-Relation in SNS Josephson Junctions},
author = {M. Fuechsle and J. Bentner and D. A. Ryndyk and M. Reinwald and W. Wegscheider and C. Strunk},
journal= {arXiv preprint arXiv:0707.4512},
year = {2009}
}
Comments
5 pages; accepted for publication in Phys. Rev. Lett