Compact molecular orbitals for strong correlations and local moment formation in frustrated metals: from models to materials

Flat bands can develop from geometrically frustrated lattices as a consequence of destructive interference, leading to enhanced correlation effects. In the case of kagome metal and its variants with active flat bands, it has been proposed that the correlation effects be studied through compact molecular orbitals [1]. The effective models constructed out of such molecular orbitals take the form of the Anderson lattice model, indicating the presence of emergent Kondo correlations. Here we consider real materials, such as the cases of the kagome [2,3,4] and pyrochlore [5] metals. We investigate the structure of the compact molecular orbitals, their implications for correlation properties, and their experimental signatures. Broad implications of our results will be discussed.

*Supported by the DOE (BES Award # DE-SC0018197) and VBFF (N00014-23-1-2870).

[1] L. Chen, et al., arXiv:2307.09431; L. Chen et al. Nat. Commun. 15, 5242 (2024); H. Hu et al., H. Hu et al Sci. Adv. 9, eadg0028 (2023).

[2] F. Xie et al, arXiv:2403.03911.

[3] L. Ye et al., Nat. Phys. (2024).

[4] Z. Ren et al, arXiv:2410.06147.

[5] J. Huang et al., Nat. Phys. 20, 603 (2024).