Magnetic charge propagation upon a 3D artificial spin-ice

• Published in: Nature communications Vol. 12; no. 1; p. 3217
• Main Authors: May, A., Saccone, M., van den Berg, A., Askey, J., Hunt, M., Ladak, S.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 28-05-2021; Nature Publishing Group; Nature Portfolio
• Subjects: 147/136; 639/766/119/2793; 639/766/119/997; Charge materials; Charge transport; Chemical potential; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ferromagnetism; Geometry; Humanities and Social Sciences; Ice; Laboratories; Magnetic fields; magnetic properties and materials; Magnetism; Monopoles; multidisciplinary; Nanowires; Physics; Propagation; Scanning electron microscopy; Science; Science (multidisciplinary); Wire
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-23480-7

Magnetic charge propagation in spin-ice materials has yielded a paradigm-shift in science, allowing the symmetry between electricity and magnetism to be studied. Recent work is now suggesting the spin-ice surface may be important in mediating the ordering and associated phase space in such materials. Here, we detail a 3D artificial spin-ice, which captures the exact geometry of bulk systems, allowing magnetic charge dynamics to be directly visualized upon the surface. Using magnetic force microscopy, we observe vastly different magnetic charge dynamics along two principal directions. For a field applied along the surface termination, local energetics force magnetic charges to nucleate over a larger characteristic distance, reducing their magnetic Coulomb interaction and producing uncorrelated monopoles. In contrast, applying a field transverse to the surface termination yields highly correlated monopole-antimonopole pairs. Detailed simulations suggest it is the difference in effective chemical potential as well as the energy landscape experienced during dynamics that yields the striking differences in monopole transport.
Two-dimensional artificial spin-ice systems have been studied for over 15 years but do not capture the detailed geometry of their bulk counterparts. Here, the authors fabricate a three-dimensional artificial spin-ice and show that the surface termination plays a crucial role in dictating the magnetic charge transport.