Disorder strength and field-driven ground state domain formation in   artificial spin ice: experiment, simulation and theory
  Quenched disorder affects how non-equilibrium systems respond to driving. In the context of artificial spin ice, an athermal system comprised of geometrically frustrated classical Ising spins with a two-fold degenerate ground state, we give experimental and numerical evidence of how such disorder washes out edge effects, and provide an estimate of disorder strength in the experimental system. We prove analytically that a sequence of applied fields with fixed amplitude is unable to drive the system to its ground state from a saturated state. These results should be relevant for other systems where disorder does not change the nature of the ground state. 
Zoe Budrikis, J. P. Morgan, J. Akerman, A. Stein, Paolo Politi, S.   Langridge, C. H. Marrows, R. L. Stamps
cond-mat.mes-hall cond-mat.dis-nn