Using X-ray beams with orbital angular momentum to probe an antiferromagnetic ground state
ORAL
Abstract
Artificial spin ice systems present an interesting platform to study magnetic interactions and dynamics. A square array of permalloy nanomagnets can be used to create an artificial antiferromagnetic lattice. Furthermore, topological defects such as edge dislocations can be introduced into the lattice. Resonant X-ray scattering from such an artificial spin ice with a defect of topological charge Z = 2 imparts an orbital angular momentum onto the scattered beam [1]. Here, we show how circular dichroism in the scattered diffraction pattern can be used to determine the ground state of the antiferromagnet and the magnetization configuration around the defect. By thermal cycling, two different degenerate ground states can be reached, and these can be differentiated using circular dichroism.
[1] J. S. Woods, X. M. Chen, et al. Phys. Rev. Lett. 126, 117201 (2021).
[1] J. S. Woods, X. M. Chen, et al. Phys. Rev. Lett. 126, 117201 (2021).
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Presenters
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Margaret R McCarter
University of California, Berkeley, Lawrence Berkeley National Laboratory
Authors
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Margaret R McCarter
University of California, Berkeley, Lawrence Berkeley National Laboratory
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ARNAB SINGH
Lawrence Berkeley National Laboratory
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Ahmad Us Saleheen
Lawrence Berkeley National Laboratory
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Ryan Tumbleson
University of California, Santa Cruz
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Anton S Tremsin
Space Sciences Laboratory, University of California, Berkeley
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Justin S Woods
University of Kentucky
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Lance E De Long
University of Kentucky
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Jeffrey T Hastings
University of Kentucky
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Sophie A Morley
Lawrence Berkeley National Laboratory
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Sujoy Roy
Lawrence Berkeley National Laboratory, ALS, Lawrence Berkeley National Lab, LBL