Abstract
In a recent article [Resta, Phys. Rev. Research 2, 023139 (2020)] it is argued, based on the dichroic sum rules derived from the modern theory of orbital magnetization, that the x-ray magnetic circular dichroism (XMCD) orbital magnetization sum rule is not providing an expectation value of the orbital angular momentum and of the orbital part of the magnetic moment, but a different quantity, also related to the breakdown of time-reversal invariance, but different. In this Comment, it is shown that this conclusion is incorrect, and that the XMCD sum rule, within its assumptions, delivers an essentially exact expectation value of the orbital angular momentum and of the orbital moment.
- Received 16 June 2020
- Revised 10 July 2020
- Accepted 30 September 2020
DOI:https://doi.org/10.1103/PhysRevResearch.2.048001
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Open access publication funded by the Max Planck Society.
Published by the American Physical Society