Abstract
Artificial spin ices (ASI) have been widely investigated as magnetic metamaterials with exotic properties governed by their geometries. In parallel, interest in x-ray photon orbital angular momentum (OAM) has been rapidly growing. Here we show that a square ASI with a patterned topological defect, a double edge dislocation, imparts OAM to scattered x rays. Unlike single dislocations, a double dislocation does not introduce magnetic frustration, and the ASI equilibrates to its antiferromagnetic (AFM) ground state. The topological charge of the defect differs with respect to the structural and magnetic order; thus, x-ray diffraction from the ASI produces photons with even and odd OAM quantum numbers at the structural and AFM Bragg conditions, respectively. The magnetic transitions of the ASI allow the AFM OAM beams to be switched on and off by modest variations of temperature and applied magnetic field. These results demonstrate ASIs can serve as metasurfaces for reconfigurable x-ray optics that could enable selective probes of electronic and magnetic properties.
| Original language | English |
|---|---|
| Article number | 117201 |
| Journal | Physical Review Letters |
| Volume | 126 |
| Issue number | 11 |
| DOIs | |
| State | Published - Mar 15 2021 |
Bibliographical note
Funding Information:The work is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award No. DE-SC0016519. The work used Timepix based soft x-ray detector, development of which is supported by DOE through award RoyTimepixDetector. X. M. C. and S. D. K. acknowledge partial support through DOE BES DE-AC02-05-CH11231 within the Nonequilibrium Magnetic Materials Program (MSMAG). This research used resources of the Advanced Light Source, which is a DOE Office of Science User Facility under Contract No. DE-AC02-05CH11231. This research used the 23-ID-1 (CSX) beamline of the National Synchrotron Light Source II, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract No. DE-SC0012704. Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. Sample characterization was performed in the Material Science Division at Argonne National laboratory and supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. This work was performed in part at the University of Kentucky Center for Nanoscale Science and Engineering and Center for Advanced Materials, members of the National Nanotechnology Coordinated Infrastructure (NNCI), which is supported by the National Science Foundation (NNCI-2025075).
Publisher Copyright:
© 2021 authors. Published by the American Physical Society.
ASJC Scopus subject areas
- Physics and Astronomy (all)