Augmented Magnetic Octupole in Kagome Antiferromagnets Detectable via X-ray Magnetic Circular Dichroism

Abstract

The magneto-optical Kerr effect (MOKE) has recently been discovered in antiferromagnetic Kagome lattice Mn3Sn. Since the compound exhibits a coplanar $120^{\circ }$ antiferromagnetic (AFM) order, the magnetic moments cancel each other, and the net magnetization is almost zero. However, the MOKE is allowed due to the lack of the time-reversal symmetry (TRS) of the AFM order. X-ray magnetic circular dichroism (XMCD) can detect a difference in up and down the spin density of states (DOS), and thus XMCD originating from the spin operator, the so-called Sz term, should be negligibly small as well as the net magnetization. Nonetheless, we show that XMCD originating from the magnetic dipole operator, the so-called Tz term, should remain uncancelled in the AFM with the broken TRS. Moreover, we clarify that there is a strong link between the Tz term and the augmented magnetic octupole (AMO), which suggests that XMCD can be an effective approach for analyzing multipole moments in antiferromagnets.

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Cited by in corpus (14)

• Complete Multipole Basis Set for Single-Centered Electron Systems
• Unified description of electronic orderings and cross correlations by complete multipole representation
• Essential role of anisotropic magnetic dipole in anomalous Hall effect
• Systematic analysis method for nonlinear response tensors
• 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
• Determination of spin chirality using x-ray magnetic circular dichroism
• Antiferromagnetic real-space configuration probed by dichroism in scattered x-ray beams with orbital angular momentum
• Giant X-ray circular dichroism in a time-reversal invariant altermagnet
• Symmetry-adapted closest Wannier modeling based on complete multipole basis set
• Sum rules for x-ray circular and linear dichroism based on complete magnetic multipole basis
• X-ray magnetic circular dichroism originating from the $T_z$ term in collinear altermagnets under trigonal crystal field
• In-plane Antiferromagnetism in Ferromagnetic Kagome Semimetal Co3Sn2S2
• Detection of ferroic octupole ordering in $d$-wave altermagnetic rutile-type compounds