The RT3B2 (R=Y, Lu, T= Co, Os) family hosts a perfect kagome lattice of T atoms, offering an interesting platform to investigate the interplay of electronic structure, superconductivity, and lattice dynamics. Here, we compare two members of this family, LuOs3B2 and YCo3B2, with similar crystallography but differing chemical composition, leading to distinct electronic correlation strengths and spin-orbit coupling effects. We confirm superconductivity in LuOs3B2 with Tc=4.75K, while YCo3B2 remains non-superconducting above 1.8K. First-principles estimates of the electron-phonon coupling for LuOs3B2 are consistent with its observed Tc and suggest a moderate coupling strength. Both materials exhibit kagome-derived electronic features, including quasi-flat bands, Dirac cones, and van Hove singularities. Fermi surface calculations reveal quasi-one-dimensional behavior along the c-axis in YCo3B2, in contrast to the more three-dimensional Fermiology of LuOs3B2. Phonon calculations for LuOs3B2 show imaginary modes, indicating potential lattice instabilities. Experimental estimates of the Wilson and Kadowaki-Woods ratios point to non-negligible electronic correlations in both compounds.
@article{arxiv.2507.04693,
title = {Tuning electronic correlations in the Kagome metals $RT_3$B$_2$},
author = {Savita Chaudhary and Armando Consiglio and Jaskaran Singh and Domenico Di Sante and Ronny Thomale and Yogesh Singh},
journal= {arXiv preprint arXiv:2507.04693},
year = {2025}
}