Low field domain wall dynamics in artificial spin-ice basis structure

Abstract

Artificial magnetic spin-ice nanostructures provide an ideal platform for the observation of magnetic monopoles. The formation of a magnetic monopole is governed by the motion of a magnetic charge carrier via the propagation of domain walls (DWs) in a lattice. To date, most experiments have been on the static visualization of DW propagation in the lattice. In this paper, we report on the low field dynamics of DW in a unit spin-ice structure measured by magnetoresistance changes. Our results show that reversible DW propagation can be initiated within the spin-ice basis. The initial magnetization configuration of the unit structure strongly influences the direction of DW motion in the branches. Single or multiple domain wall nucleation can be induced in the respective branches of the unit spin ice by the direction of the applied field. V

Advances in artificial spin ice

“…Taking advantage of this asymmetry, a domain wall passing through tailored Y-junctions, which are the basic units of connected artificial kagome spin ice, can be used to perform logic operations 62,63 . However, care is needed because the walls may transform into domain walls of opposite chirality for particular magnetic fields and geometries 64,65 , and the propagation behaviour of the domain walls depends on the magnitude and orientation of the applied magnetic fields [66][67][68] . To circumvent these effects, the geometry of the Y-junctions can be modified so that the symmetry of the branches is reduced, giving a deterministic domain wall path that is independent of the domain-wall chirality 69 .…”