Ratchet effect: Demonstration of a relativistic fluxon diode - art. no. 077002

We report the observation of the ratchet effect for a relativistic flux qua ntum trapped in an annular Josephson junction embedded in an inhomogeneous magnetic field. In such a solid state system, mechanical quantities are pro portional to electrical quantities, so that the ratchet effect represents t he realization of a relativistic-flux-quantum-based diode. Man static volta ge response, equivalent to direct fluxon motion,is experimentally demonstra ted in such a diode for deterministic as well as stochastic oscillating cur rent forcing.