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arXiv · 1806.04461

Field-induced magnetic charge in a cubic Laves compound UAl2

S. W. Lovesey·D. D. Khalyavin·G. van der Laan
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Abstract

Magnetic diffraction of polarized neutrons by the cubic Laves compound UAl2 in a magnetic field has unveiled weak Bragg spots that are nominally forbidden. On the one hand, they can be viewed as magnetic analogues of the basis-forbidden (2, 2, 2) reflection in diamond-type structures that has been painstakingly and frequently investigated over almost a century. Alternatively, the pattern of weak intensities can be assigned to Dirac multipoles imbedded in field-induced magnetic charge. To this end, a published diffraction pattern is successfully confronted with intensities calculated from the appropriate magnetic space-group that includes Dirac dipoles (anapoles) to describe the basis-forbidden magnetic reflections, and conventional (axial) dipole and octupole multipoles to describe basis-allowed magnetic reflections.

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S. W. Lovesey, D. D. Khalyavin, G. van der Laan. 2018-06-12. Field-induced magnetic charge in a cubic Laves compound UAl2. https://doi.org/10.1088/1742-6596/1316/1/012004

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