X-ray Orbital Angular Momentum from Artificial Antiferromagnets containing Edge Dislocations

Artificial spin lattices (ASLs), including artificial spin ices, consist of patterned magnetic nanostructures that mimic Ising spins. Here we show that a permalloy, square ASL with a double edge dislocation exhibits an ordered antiferromagnetic ground state, unlike square ASLs with a single dislocation.¹ We demonstrate that soft x-rays resonantly scattered from this magnetic texture carry orbital angular momentum. Moreover, x-ray OAM from these samples can be modulated using and temperature and applied magnetic fields. X-ray beams carrying orbital angular momentum (OAM) have potential applications in nanoscale imaging, spectroscopy, and manipulation, but current means of generating x-ray OAM are difficult to modulate or reconfigure.² Scattering from ASLs may offer a potential path to flexible control of x-ray OAM.

¹ Drisko et al. Topological frustration of artificial spin ice, Nature Communications (2017).
² Lee et al., Laguerre–Gauss and Hermite–Gauss soft X-ray states generated using diffractive optics, Nature Photonics (2019).