Three Dimensional Artificial Spin Ice

SPICE Workshop on Nanomagnetism in 3D, April 30th - May 2nd 2024

Laura jane Heyderman

Artificial spin ices are designer metamaterials consisting of coupled nanomagnets with frustrated magnetic configurations that have traditionally been arranged in 2D on various lattices. They exhibit a host of fascinating emergent phenomena including magnetic monopoles, phase transitions and vertex frustration [1-4]. The nanomagnets are often made of permalloy and arranged on the square or kagome lattice. However, the field has grown tremendously to encompass a large variety of lattices, some aperiodic and some in 3D, each bringing their own fascinating physics. Artificial spin ices not only offer prospects for addressing interesting fundamental questions, but also for the development of novel devices.
In keeping with the theme of this workshop, I will focus on discussing methods used to manufacture and characterize three-dimensional artificial spin ice. I will explain how electron beam lithography, two photon laser lithography, self-assembly methods and, to some extent, focused electron beam induced deposition have been used to manufacture 3D systems. I will also explain and how magnetic force microscopy, photoemission electron microscopy and synchrotron x-ray laminography have been used to characterize them. In doing so, I will highlight the scientific allure of three-dimensional artificial spin ice, and touch on various work, theory and experimental, to elucidate the magnetization dynamics at slow and fast timescales.

References
[1] S.H. Skjærvø, C.H. Marrows, R.L. Stamps, L.J. Heyderman, Nat. Rev. Phys. 2, 13 (2020)
[2] S. Gliga, E. Iacocca, O.G. Heinonen, APL Materials, 8, 040911 (2020)
[3] L.J Heyderman and R.L. Stamps, J. Phys.: Condens. Matter 25, 363201 (2013)
[4] C. Nisoli, R. Moessner, P. Schiffer Rev. Mod. Phys. 85, 1473 (2013)