Emergent magnetic monopole dynamics in macroscopically degenerate artificial spin ice

• DOI: 10.1126/sciadv.aav6380
• Publication Date: 2019-02-09T00:15:30Z
• Authors: Alan Farhan; Michael Saccone; Charlotte F. Pete...; Scott Dhuey; Rajesh V. Chopdekar; Yen-Lin Huang; Noah Kent; Zuhuang Chen; Mikko J. Alava; Thomas Lippert; Andreas Scholl; Sebastiaan van Di...
• Keywords: Spin ice; Dynamics

Magnetic monopoles, proposed as elementary particles that act isolated magnetic south and north poles, have long attracted research interest analogs to electric charge. In solid-state physics, a classical analog these elusive has emerged topological excitations within pyrochlore spin ice systems. We present the first real-time imaging of emergent monopole motion in macroscopically degenerate artificial system consisting thermally activated Ising-type nanomagnets lithographically arranged onto pre-etched silicon substrate. A real-space characterization monopoles framework Debye-Hückel theory is performed, providing visual evidence defects like plasma Coulomb-type charges. contrast vertex purely two-dimensional square ice, are free evolve divergence-free vacuum, Coulomb phase, for which features form pinch-point singularities structure factors observed.