Frustration, the presence of competing interactions, is ubiquitous in the physical sciences
and is a source of degeneracy and disorder, which in turn gives rise to new and interesting …

Lithographic processing and film growth technologies are continuing to advance, so that it is
now possible to create patterned ferroic materials consisting of arrays of sub-1 μm elements …

Arrays of suitably patterned and arranged magnetic elements may display artificial spin-ice
structures with topological defects in the magnetization, such as Dirac monopoles and Dirac …

Over the past few years, the study of magnetization dynamics in artificial spin ices has
become a vibrant field of study. Artificial spin ices are ensembles of geometrically arranged …

Frustrated arrays of interacting single-domain nanomagnets provide important model
systems for statistical mechanics, as they map closely onto well-studied vertex models and …

Artificially frustrated spin-ice systems are of considerable interest since they simulate the
spin frustration and concomitant rich behavior exhibited by atoms on a crystal lattice in …

We study the impact of geometry on magnetostatically frustrated single-domain nanomagnet
arrays. We examine square and hexagonal lattice arrays, as well as a brickwork geometry …

We report a magneto-optical Kerr effect study of the collective magnetic response of artificial
square spin ice, a lithographically defined array of single-domain ferromagnetic islands. We …

Dirac strings in spin ices are lines of reversed dipoles joining two quasiparticle excitations.
These excitations behave as unbound emergent monopoles if the tension of Dirac strings …

We have studied the magnetic-moment configurations of different geometry clusters of single-
domain nanoscale ferromagnetic islands. The clusters consisted of four islands arranged in …