2023/08/14 by Zhou, Benjamin T., Franz, Marcel
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
paper · doi:10.48550/arxiv.2308.07408
Based on symmetry arguments and the latest density functional results for the copper-substituted lead phosphate apatite (`LK-99'), we show that, at the non-interacting level, the material is an inversion-asymmetric Weyl semimetal. A pair of Weyl nodes with opposite chiralities emerge at different energies in the vicinity of the time-reversal-invariant Γ and \rm A points of the 3D Brillouin zone. These are characterized by unusual Weyl charges of C\rm W = ± 2 and are connected by two branches of topologically protected Fermi arc states on surfaces parallel to the principal c-axis. We further study important effects of the atomic spin-orbit coupling on the band structure and the electronic properties of the material in general. Possible implications of the proposed band topology on the strong correlation physics are also discussed.