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arXiv · 1412.2536

Anapoles and other magneto-electric multipoles in BaFe2Se3

S W Lovesey·D D Khalyavin
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Abstract

We submit that the magnetic space-group Cac (#9.41) is consistent with the established magnetic structure of BaFe2Se3, with magnetic dipole moments in a motif that uses two ladders [Caron J M et al 2011 Phys. Rev. B 84 180409(R)]. The corresponding crystal class m1' allows axial and polar dipoles and forbids bulk ferromagnetism. The compound supports magneto-electric multipoles, including a magnetic charge (monopole) and an anapole (magnetic toroidal dipole) visible in the Bragg diffraction of x-rays and neutrons. Our comprehensive simulation of neutron Bragg diffraction by BaFe2Se3 exploits expressions of a general nature that can be of use with other magnetic materials. Electric toroidal moments are also allowed in BaFe2Se3. A discussion of our findings for resonant x-ray Bragg diffraction illustrates the benefit of a common platform for neutron and x-ray diffraction.

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S W Lovesey, D D Khalyavin. 2014-12-08. Anapoles and other magneto-electric multipoles in BaFe2Se3. https://arxiv.org/abs/1412.2536

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