Biologically inspired devices for easily controlling the motion of magnetic flux quanta

Motor proteins employ non-equilibrium fluctuations in anisotropic media to transport cargo at the cellular level. Here we consider anisotropic pinning to transport magnetic flux quanta inside superconductor. In particular, we consider: (1) composite pins by superimposing two interpenetrating arrays of weak and strong pinning centers; (2) triangular blind antidots; (3) V-shaped pinning sites. Specifically, we study stochastic transport of fluxons by alternating current (AC) rectification. Our simulated systems provide fluxon pumps, or fluxon “rectifiers”, because the applied electrical AC force is transformed into a net DC motion of fluxons. The asymmetry of the ratchet-shaped pinning landscape induce this “diode” effect, which can have important applications in devices, like SQUID magnetometers, and for fluxon optics, including convex and concave fluxon lenses.