Hysteresis multicycles in nanomagnet arrays

Abstract

We predict two new physical effects in arrays of single-domain nanomagnets by performing simulations using a realistic model Hamiltonian and physical parameters. First, we find hysteretic multicycles for such nanomagnets. The simulation uses continuous spin dynamics through the Landau-Lifshitz-Gilbert (LLG) equation. In some regions of parameter space, the probability of finding a multicycle is as high as ~0.6. We find that systems with larger and more anisotropic nanomagnets tend to display more multicycles. This result demonstrates the importance of disorder and frustration for multicycle behavior. We also show that there is a fundamental difference between the more realistic vector LLG equation and scalar models of hysteresis, such as Ising models. In the latter case, spin and external field inversion symmetry is obeyed but in the former it is destroyed by the dynamics, with important experimental implications.

7 pages, 2 figures

References in corpus (5)

• Hysteresis and hierarchies: dynamics of disorder-driven first-order phase transformations
• Disorder-induced microscopic magnetic memory
• Quasistatic x-ray speckle metrology of microscopic magnetic return point memory
• Hysteresis in the Random Field Ising Model and Bootstrap Percolation
• Subharmonics and Aperiodicity in Hysteresis Loops

Cited by in corpus (5)

• Multiple memory formation in glassy landscapes
• Mechanism for nonequilibrium symmetry breaking and pattern formation in magnetic films
• Effect of dipolar interactions on the magnetization of a cubic array of nanomagnets
• Non-converging hysteretic cycles in random spin networks
• Disorder-induced magnetic memory: Experiments and theories