Microwave irradiation of Nb-InAs-Nb junctions reveals frequency-doubled Josephson currents which persist to high temperatures, in the absence of a critical current. A nonequilibrium dynamical model, based on time-dependent Andreev bound states, successfully accounts for the resulting half-integer Shapiro step and an enhancement in the conductance near zero bias.
@article{arxiv.cond-mat/9901006,
title = {Nonequilibrium ac Josephson effect in mesoscopic Nb-InAs-Nb junctions},
author = {K. W. Lehnert and N. Argaman and H. -R. Blank and K. C. Wong and S. J. Allen and E. L. Hu and H. Kroemer},
journal= {arXiv preprint arXiv:cond-mat/9901006},
year = {2009}
}
Comments
4 pages, 4 embedded figures, to be published in Phys. Rev. Lett. An HTML presentation of these results is available at http://www.qi.ucsb.edu/Konrad/summary/summary.htm