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arXiv · 2502.11765

Square skyrmion lattice in multiorbital $f$-electron systems

Yan Zha·Satoru Hayami
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Abstract

We report the emergence of a square-shaped skyrmion lattice in multi-orbital $f$-electron systems with easy-axis magnetic anisotropy on a centrosymmetric square lattice. By performing mean-field calculations for an effective localized model consisting of two Kramers doublets, we construct the low-temperature phase diagram in a static external magnetic field. Consequently, we find that a square-shaped skyrmion lattice with the skyrmion number of one appears in the intermediate-field region when the crystal field splitting between the two doublets is small. Furthermore, we identify another double-$Q$ state with a nonzero net scalar chirality at zero- and low-field regions, which is attributed to the help of the multi-orbital degree of freedom. Our results offer another route to search for skyrmion-hosting materials in centrosymmetric $f$-electron tetragonal systems with multi-orbital degrees of freedom, e.g., Ce-based compounds. This contrasts with conventional other $f$-electron systems hosting skyrmion lattices, such as Gd- and Eu-based compounds without orbital angular momentum.

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Yan Zha, Satoru Hayami. 2025-02-17. Square skyrmion lattice in multiorbital $f$-electron systems. https://doi.org/10.1103/physrevb.111.165155

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