We demonstrate experimentally the operation of a deterministic Josephson ratchet with tunable asymmetry. The ratchet is based on a φ Josephson junction with a ferromagnetic barrier operating in the underdamped regime. The system is probed also under the action of an additional dc current, which acts as a counter force trying to stop the ratchet. Under these conditions the ratchet works against the counter force, thus producing a non-zero output power. Finally, we estimate the efficiency of the φ Josephson junction ratchet.
@article{arxiv.1607.07717,
title = {Tunable $\varphi$ Josephson Junction ratchet},
author = {R. Menditto and H. Sickinger and M. Weides and H. Kohlstedt and D. Koelle and R. Kleiner and E. Goldobin},
journal= {arXiv preprint arXiv:1607.07717},
year = {2016}
}