%0 Journal Article
%A Rollano, V.
%A Muñoz Noval, Álvaro
%A Gómez, A.
%A Valdés Bango, F.
%A Martín, J.I.
%A Vélez, M.
%A Osorio, M. R.
%A Granados, D.
%A González Herrera, Elvira María
%A Vicent López, José Luis
%T Topologically protected superconducting ratchet effect generated by spin-ice nanomagnets
%D 2019
%@ 0957-4484
%U https://hdl.handle.net/20.500.14352/13328
%X We have designed, fabricated and tested a robust superconducting ratchet device based on topologically frustrated spin ice nanomagnets. The device is made of a magnetic Co honeycomb array embedded in a superconducting Nb film. This device is based on three simple mechanisms: (i) the topology of the Co honeycomb array frustrates in-plane magnetic configurations in the array yielding a distribution of magnetic charges which can be ordered or disordered with in-plane magnetic fields, following spin ice rules; (ii) the local vertex magnetization, which consists of a magnetic half vortex with two charged magnetic Neel walls; (iii) the interaction between superconducting vortices and the asymmetric potentials provided by the Neel walls. The combination of these elements leads to a superconducting ratchet effect. Thus, superconducting vortices driven by alternating forces and moving on magnetic half vortices generate a unidirectional net vortex flow. This ratchet effect is independent of the distribution of magnetic charges in the array.
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