title: Degeneracy and criticality from emergent frustration in artificial spin ice.
abstract: Although initially introduced to mimic the spin-ice pyrochlores, no artificial spin ice has yet exhibited the expected degenerate ice phase with critical correlations similar to the celebrated Coulomb phase in the pyrochlore lattice. Here we study a novel artificial spin ice based on a vertex-frustrated rather than pairwise frustrated geometry and show that it exhibits a quasicritical ice phase of extensive residual entropy and, significantly, algebraic correlations. Interesting in its own regard as a novel realization of frustration in a vertex system, our lattice opens new pathways to study defects in a critical manifold and to design degeneracy in artificial magnetic nanoarrays, a task so far elusive.
authors.affiliation: Theoretical Division and Center for Nonlinear Studies, LANL, Los Alamos, New Mexico 87545, USA.
authors.forename: Gia-Wei
authors.initials: GW
authors.lastname: Chern
authors.forename: Muir J
authors.initials: MJ
authors.lastname: Morrison
authors.forename: Cristiano
authors.initials: C
authors.lastname: Nisoli