Electron correlations in the kagome flat band metal $\rm CsCr_3Sb_5$

• DOI: 10.48550/arxiv.2403.03911
• Publication Date: 2024-03-06
• Authors: Fang Xie; Yuan Fang; Ying Li; Yuefei Huang; L. Chen; Chandan Setty; Shouvik Sur; Boris I. Yakobson; Roser Valentí; Qimiao Si
• Keywords: Condensed Matter - Strongly Correlated Electrons; Condensed Matter - Materials Science; Strongly Correlated Electrons (cond-mat.str-el); Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences

Kagome metals offer a unique platform for investigating robust electron-correlation effects because of their lattice geometry, flat bands and multi-orbital nature. In the cases with active bands, recent theoretical studies have pointed to rich phase diagram that contains not only electronic orders but also quantum criticality. $\rm CsCr_3Sb_5$ has emerged as strong candidate exploring such new physics. Here, using effective tight-binding models obtained from ab initio calculations, we study correlations symmetries on structure CsCr_3 Sb_5$. The model Fermi surface comprise multiple Cr-$d$ orbitals Sb-$p$ orbitals. introduction Hubbard-Kanamori interactions leads orbital-selective band renormalization dominated by $d_{xz}$ band, concurrently producing emergent very close level. Our analysis sets stage further investigations into properties CsCr_3Sb_5$, including orders, criticality unconventional superconductivity, which promise shed much light materials frustrated lattices bring about connections correlation physics variety strongly correlated systems.