Dynamics of a macroscopic artificial spin ice: experiment and modeling

Artificial spin ices (ASIs) are ensembles of geometrically structured, interacting magnetic nano-elements that exhibit frustration [1]. Here, we present a macroscopic ASI where 1-inch magnets mounted on low-friction rotors are arranged in a square lattice. The system can be driven into a nonlinear regime by an external coil with a field oscillating in the 1 to 20 Hz range. Mixing and coupling between high-symmetry modes is observed, evidenced by an increase in the spectral content at approximately 10 Hz. The dynamics are experimentally captured by a high-frame-rate camera and then digitized to recover the spectrum for each magnet. Modeling based on the torque equation for each elongated magnet and their coupling using a monopole-charge approximation [2] reproduces the dynamics with remarkable accuracy. While at completely different spatial and temporal scales, these dynamics are similar to those observed at the nanoscale when ASIs are driven into a nonlinear regime [3]. Our macroscopic ASI can be considered as a testbed for nonlinear phenomena at a scale appropriate for dissemination to the general public.

References



[1] S. H. Skjærvø et al., Nat. Rev. Phys. 2, 13 – 28 (2020)

[2] P. Mellado, A. Concha, and L. Mahadevan, Phys. Rev. Lett. 109, 257203 (2012)

[3] Lendinez et al., Nature Communications 14, 3419 (2023)