Antiferromagnetic real-space configuration probed by dichroism in scattered x-ray beams with orbital angular momentum
arXiv:2205.03475 · doi:10.1103/PhysRevB.107.L060407
Abstract
X-ray beams with orbital angular momentum (OAM) are a promising tool for x-ray characterization techniques. Beams with OAM have a helicity--an azimuthally varying phase--which leads to a gradient of the light field. New material properties can be probed by utilizing the helicity of an OAM beam. Here, we demonstrate a novel dichroic effect in resonant diffraction from an artificial antiferromagnet with a topological defect. We found that the scattered OAM beam has circular dichroism at the antiferromagnetic Bragg peak whose sign is coupled to its helicity, which reveals the real-space configuration of the antiferromagnetic ground state. Thermal cycling of the artificial antiferromagnet can change the ground state, as indicated by reversal of the sign of circular dichroism. This result is one of the first demonstrations of a soft x-ray spectroscopy characterization technique utilizing the OAM of x-rays. This helicity-dependent circular dichroism exemplifies the potential to utilize OAM beams to probe matter in a way that is inaccessible using currently available x-ray techniques.
References in corpus (7)
- Resonant Elastic Soft X-Ray Scattering
- Hard X-ray helical dichroism of disordered molecular media
- Switchable X-ray Orbital Angular Momentum from an Artificial Spin Ice
- Presence of x-ray magnetic circular dichroism effect for zero-magnetization state in antiferromagnetism
- Observation of spontaneous x-ray magnetic circular dichroism in a chiral antiferromagnet
- On the possibility to detect multipolar order in URuSi by the electric quadrupolar transition of resonant elastic X-ray scattering
- Determination of spin chirality using x-ray magnetic circular dichroism