Dirac-like ferrimagnet CeAuGeBi as a member of a homologous series of square-net topological materials

山下 淳志*; 木俣 基; 酒井 英明*; 他13名*

Yamashita, Atsushi*; Kimata, Motoi; Sakai, Hideaki*; 13 of others*

Square-net compounds with the HfCuSi-type framework have been a promising platform for realizing topological electronic states and their interplay with quantum many-body phenomena. In these materials, the transition-metal tetrahedral layer sandwiched between square-net layers plays a crucial role in determining the correlated physical properties, yet their structural variety has been limited to the single-layer type. Here, we report the discovery of CeAuGeBi, a new square-net compound that represents the bilayer member of a homologous series bridging the HfCuSi-type CeAuBi (112 phase) and ThCrSi-type CeAuGe2 (122 phase). The bilayer structure of CeAuGeBi is formed by combining two tetrahedral layers of the 112 phase through the insertion of a 122-like block, resulting in two mixed-anion antifluorite-type layers. Intriguingly, both the magnetic and electronic structures are substantially modified relative to the 112 phase.