1. Topologically protected superconducting ratchet effect generated by spin-ice nanomagnets
- Author
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Ministerio de Economía y Competitividad (España), Comunidad de Madrid, Vicent, J. L. [0000-0001-9343-7671], Rollano, Víctor, Muñoz-Noval, Alvaro, Gómez, Alicia, Valdés-Bango, F., Martín, José Ignacio, Vélez, María, Osorio, M. R., Granados, D., González, Elvira M., Vicent, J. L., Ministerio de Economía y Competitividad (España), Comunidad de Madrid, Vicent, J. L. [0000-0001-9343-7671], Rollano, Víctor, Muñoz-Noval, Alvaro, Gómez, Alicia, Valdés-Bango, F., Martín, José Ignacio, Vélez, María, Osorio, M. R., Granados, D., González, Elvira M., and Vicent, J. L.
- Abstract
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 Néel walls; (iii) the interaction between superconducting vortices and the asymmetric potentials provided by the Néel 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.
- Published
- 2019