Using a custom-FPGA architecture to extend the scale of atomistic magnetic spin simulations

New computational solutions are required to understand how atomic-scale properties affect magnetic behaviour at micrometer dimensions. We describe a field-programmable-gate-array (FPGA) based simulation of a dilute antiferromagnet with a large number of Ising spins using Glauber dynamics. The simple atomic model qualitatively reproduces experimental findings when scaled up to sufficiently large spatial dimensions, and provides insight into the finite size thresholds separating nanoscale from microscale behaviour. A real-time visualisation module was used to study the dynamics of the fractal domain structure and non-exponential relaxation mechanism. A performance comparison with contemporary GPU and CPU implementations suggests that a FPGA route is a competitive alternative.