Experimental evidence of a {\phi} Josephson junction
Abstract
We demonstrate experimentally the existence of Josephson junctions having a doubly degenerate ground state with an average Josephson phase \psi=\pm{\phi}. The value of {\phi} can be chosen by design in the interval 0<{\phi}<\pi. The junctions used in our experiments are fabricated as 0-{\pi} Josephson junctions of moderate normalized length with asymmetric 0 and {\pi} regions. We show that (a) these {\phi} Josephson junctions have two critical currents, corresponding to the escape of the phase {\psi} from -{\phi} and +{\phi} states; (b) the phase {\psi} can be set to a particular state by tuning an external magnetic field or (c) by using a proper bias current sweep sequence. The experimental observations are in agreement with previous theoretical predictions.
Cite
@article{arxiv.1207.3013,
title = {Experimental evidence of a {\phi} Josephson junction},
author = {H. Sickinger and A. Lipman and M. Weides and R. G. Mints and H. Kohlstedt and D. Koelle and R. Kleiner and E. Goldobin},
journal= {arXiv preprint arXiv:1207.3013},
year = {2012}
}