Emergent magnetic monopole dynamics in macroscopically degenerate artificial spin ice

Alan Farhan*, Michael Saccone, Charlotte F. Petersen, Scott Dhuey, Rajesh V. Chopdekar, Yen Lin Huang, Noah Kent, Zuhuang Chen, Mikko J. Alava, Thomas Lippert, Andreas Scholl, Sebastiaan van Dijken

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

26 Citations (Scopus)
142 Downloads (Pure)

Abstract

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

Original languageEnglish
Article numbereaav6380
Pages (from-to)1-8
JournalScience Advances
Volume5
Issue number2
DOIs
Publication statusPublished - 8 Feb 2019
MoE publication typeA1 Journal article-refereed

Keywords

  • MAGNETIC MONOPOLES
  • spin ice
  • nanomagnetism
  • XMCD

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  • Cite this

    Farhan, A., Saccone, M., Petersen, C. F., Dhuey, S., Chopdekar, R. V., Huang, Y. L., Kent, N., Chen, Z., Alava, M. J., Lippert, T., Scholl, A., & van Dijken, S. (2019). Emergent magnetic monopole dynamics in macroscopically degenerate artificial spin ice. Science Advances, 5(2), 1-8. [eaav6380]. https://doi.org/10.1126/sciadv.aav6380, https://doi.org/10.1126/sciadv.aav6380