Artificial spin ices get mechanical

Artificial spin ices (ASI) are magnetic metamaterials that exhibit frustration and reconfigurable magnetization dynamics. Profs. Iacocca and Bozhko aimed to demonstrate such dynamics with macroscopic artificial spin ice: an array of permanent magnets supported by specially designed hinges that allow for low-friction rotation. The 60 one-inch-magnet array was created with the aid of graduate student Renju Peroor and undergraduate student Lawrence Scafuri. However, this macro-ASI system held many surprises in store.

Combining high-speed camera detection and detailed numerical simulations, the authors found that macro-ASI can stabilize frequency combs: a spectrum of discrete and equally spaced frequency components. This comb appears due to a Hopf bifurcation that drives the system into a non-equilibrium state where amplitude and phases are modulated in a nonlinear fashion. These results are promising for enhancing nonlinear dynamics in nanoscopic ASIs insofar as the dynamic coupling strength is increased.

The results were published in R. R. Peroor et al., Phys. Rev. Applied 23, 044010 (2025) and received editors’ suggestion distinction.