Determination of spin chirality using x-ray magnetic circular dichroism

DOI: 10.1103/PhysRevB.104.094414

Authors: Gerrit Van Der Laan (Diamond Light Source)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review B , VOL 104

State: Published (Approved)
Published: September 2021

Abstract: A threefold symmetric kagome lattice that has negative spin chirality can give a nonzero x-ray magnetic circular dichroism (XMCD) signal, despite the total spin moment amounting to zero. In order to explain this, I present here a rule for the rotational symmetry invariance of the XMCD signal. A necessary condition is the existence of an anisotropic XMCD signal for the local magnetic atom, which can arise from a spin anisotropy either in the ground state or the final state. The angular dependence of the XMCD as a function of the beam direction has an unusual behavior. The maximum dichroism is not aligned along the spin direction, but depends on the relative orientation of the spin with respect to the atomic orientation. Therefore, different geometries can result in the same angular dependence, and the spin direction can only be determined if the atomic orientation is known. The consequences for the x-ray magneto-optical sum rules are given. The integrated XMCD signals are proportional to the anisotropy in the orbital moment and the magnetic dipole term, where the isotropic spin moment drops out.

Journal Keywords: Magnetism; 2-dimensional systemsKagome lattice; X-ray magnetic circular dichroism

Diamond Keywords: Ferromagnetism; Antiferromagnetism

Subject Areas: Physics, Materials


Technical Areas: Theoretical Physics

Added On: 18/09/2021 12:23

Documents:
PhysRevB.104.094414.pdf

Discipline Tags:

Quantum Materials Physics Magnetism Materials Science Theoretical Physics

Technical Tags:

Spectroscopy Circular Dichroism (CD) X-ray Magnetic Circular Dichroism (XMCD)