Multiple reversals of vortex ratchet effects in a superconducting strip with inclined dynamic pinning landscape* *Project supported by the National Natural Science Foundation of China (Grant Nos. 11702034, 11972298, and 11702218), the China Postdoctoral Science Foundation (Grant No. 2019M663812), the Fundamental Research Funds for the Central Universities, China (Grant Nos. 300102129104, 3102018zy013, and 3102017jc01003), and the Young Talent Fund of

Abstract

Using time-dependent Ginzburg–Landau formalism, we investigate the multiple reversals of ratchet effects in an unpatterned superconducting strip by the tilted dynamic pinning potential. In the case of collinear sliding potential and Lorentz force, vortices are always confined in the channels induced by sliding potential. However, due to the inclination angle of sliding pinning potential with respect to the Lorentz force, vortices could be driven out of the channels, and unexpected results with multiple reversals of vortex rectifications are observed. The mechanism of multiple reversals of vortex rectifications is explored by analyzing different vortex motion scenarios with increasing ac current amplitudes. The multiple reversals of transverse and longitudinal ratchet effects can be highly controlled by ac amplitude and dynamic pinning velocity. What’s more, at certain large current the ratchet effect reaches strongest within a wide range of pinning sliding velocity.