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arXiv · 2408.17389

Multipolar multiferroics in $4d^2$/$5d^2$ Mott insulators

Saikat Banerjee·Stephan Humeniuk·Alan R. Bishop·Avadh Saxena·Alexander V. Balatsky
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Abstract

We extend the concept of conventional multiferroicity \ -- where ferroelectric and ferromagnetic orders coexist \ -- to include multipolar degrees of freedom. Specifically, we explore how this phenomenon emerges in $4d^2/5d^2$ Mott insulators with strong spin-orbit and Hund's couplings. Our study uncovers the origin of magnetic multipolar interactions in these systems and demonstrates that a combination of quadrupolar and octupolar magnetic order can simultaneously induce both electrical quadrupolar moments and ferroelectric polarization. By expanding the multiferroic framework to higher-order multipoles, we reveal the possibility of coexisting multipolar orders of different or same ranks, paving the way for new functional properties in a large class of strongly correlated materials.

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Saikat Banerjee, Stephan Humeniuk, Alan R. Bishop, Avadh Saxena, Alexander V. Balatsky. 2024-08-30. Multipolar multiferroics in $4d^2$/$5d^2$ Mott insulators. https://doi.org/10.1103/physrevb.111.l201107

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