Research Highlight

Field-tunable toroidal moment in a chiral-lattice magnet

We studied the complex magnet BaCoSiO4 with several experimental techniques and density functional theory (DFT) calculations. Inelastic neutron scattering yields an apparently very complex magnetic structure that is hard to rationalize. However, DFT based energy mapping comes up with a Heisenberg Hamiltonian that suddely explains almost all observations. The strongest couplings divide the crystal into three intertwined sublattices. In combination with small canting due to Dzyaloshinskii-Moriya interactions the sublattices turn out to have toroidal moments that can be switched by small magnetic fields due to subleading exchange interactions. This provides a mechanism to easily control the ferritoroidal and ferrotoroidal states of the system.

L. Ding, X. Xu, H. O. Jeschke,* X. Bai, E. Feng, A. S. Alemayehu, J. Kim, F. Huang, Q. Zhang, X. Ding, N. Harrison, V. Zapf, D. Khomskii, I. I. Mazin, S.-W. Cheong, H. Cao

Nat. Commun. 12, 5339 (2021) <https://doi.org/10.1038/s41467-021-25657-6>