Dynamics of Magnetic Charges in Artificial Spin Ice

Abstract

Artificial spin ice has been recently implemented in two-dimensional arrays of mesoscopic magnetic wires. We propose a theoretical model of magnetization dynamics in artificial spin ice under the action of an applied magnetic field. Magnetization reversal is mediated by domain walls carrying two units of magnetic charge. They are emitted by lattice junctions when the local field exceeds a critical value Hc required to pull apart magnetic charges of opposite sign. Positive feedback from Coulomb interactions between magnetic charges induces avalanches in magnetization reversal.

Artificial kagome spin ice: dimensional reduction, avalanche control and emergent magnetic monopoles

“…figure 1b. We also emphasize that we consider islands that are entirely isolated from each other and hence only exhibit dipolar interaction, in contrast to the interconnected honeycomb networks in [10,11,13].…”

Angular-dependent magnetization reversal processes in artificial spin ice

“…13,14 These DWs typically originate at the edges of the sample as the reversal in the center of the array is constrained by the magnetization of the surrounding bars. 15 Therefore, the magnetization reversal in one bar triggers the reversal in neighbouring bars and leads to chains of reversal following Dirac strings in avalanche-like behavior. [15][16][17] Furthermore, in isolated bar systems, monopole chirality may provide additional factors that influence the reversal paths in such systems.…”

“…15 Therefore, the magnetization reversal in one bar triggers the reversal in neighbouring bars and leads to chains of reversal following Dirac strings in avalanche-like behavior. [15][16][17] Furthermore, in isolated bar systems, monopole chirality may provide additional factors that influence the reversal paths in such systems. 18 Varying the angle of the applied field with respect to the geometrical structuring also offers a route to influence the magnetization reversal by biasing particular sub-lattice directions.…”

“…Here the angular dependence of the nucleation of a DW from a vertex has been reveal an angular shift in the minimum DW nucleation field due to an asymmetric magnetization distribution at the vertex. 15,19,20 Numerical analysis based on this offset model predicts the order of reversal for the different sub-lattices and sequences of these reversals. 19 Here the role of the nucleation process for a DW at the vertices is explored in detail through a series of micromagnetic simulations and experimental measurements on artificial spin ice structures.…”

Molecular Em Fields and Dynamical Responses in Solids With Magnetic Charges

“…A contribution to the interpretation of these monopoles was carried out in 1938 by Jordan [2] and in 1974 Hooft [3] and Polyakov [4] introduced the magnetic monopole idea as a contribution to the second great unification of the three more intense forces, electromagnetic, weak nuclear and strong nuclear interactions. These and other theoretical analysis have provoked that the experimental pursuit of the magnetic monopole manifestation is an issue that is both liminal and subliminally present since 1982 [5] and now is receiving a payment of attention in both high energy physics [6] and solid state (SS) physics [6][7][8][9][10][11][12][13][14][15].…”