Direct Evidence of Topological Defects in Electron Waves through Nanoscale Localized Magnetic Charge

Charudatta Phatak*, Amanda Petford-Long

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Topological concepts play an important role in, and provide unique insights into, many physical phenomena. In particular topological defects have become an active area of research due to their relevance to diverse systems including condensed matter and the early universe. These defects arise in systems during phase transitions or symmetry-breaking operations that lead to a specific configuration of the order parameter that is stable against external perturbations. In this work, we experimentally show that excitations or defects carrying magnetic charge in artificial spin ices introduce a topological defect in incident coherent electron waves. This results in the formation of a localized electron vortex beam carrying orbital angular momentum that is directly correlated with the magnetic charge. This work provides unique insight into the interaction of electrons with magnetically charged excitations and the effect on their topology thereby opening new possibilities to explore exotic scattering and quantum effects in nanoscale condensed-matter systems.

Original languageEnglish (US)
Pages (from-to)6989-6994
Number of pages6
JournalNano letters
Issue number11
StatePublished - Nov 14 2018


  • Lorentz transmission electron microscopy
  • Nanoscale artificial spin ices
  • vortex beams

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering


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