Coexistence of magnetic textures and Weyl topology in Co3Sn2SeS*

The shandite compounds Co3Sn2S2 and Co3Sn2Se2 have garnered great interest due to the topological electronic structure that drives a large momentum space berry curvature. Previous results have shown an anomalous Hall/Nernst effect that is maximized in the inversion symmetric bulk and predicted quantized effects in these layered materials. While the fabrication of Co3Sn2Se2 still remains a challenge, there have been experimental results showing the stability of Co3Sn2SeS. Yet, there is little theoretical and computational understanding of the magnetic and electronic structure. In this work, we use first principles calculations and symmetry analysis to compare the effects of Co3Sn2SeS, which lacks inversion symmetry, with the previously mentioned compounds. Due to the lack of inversion symmetry, we find that the Co3Sn2SeS shows a sizable bulk Dzyaloshinkii-Moriya Interaction which is beneficial for the stabilization of topological magnetic structures such as skyrmions. We further investigate the interplay between the real space magnetic structure and the topological electronic structure. Our results show the phase diagram for the stability of the Weyl crossings with distinct magnetic textures and the viability for the stabilization of skyrmions. Co3Sn2SeS will thus serve as one of the first real systems to simultaneously host both skyrmion and Weyl feature which can lead to future possibilities of intrinsic skyrmion manipulation via the chiral anomalous effects.