Speaker
Description
Quantum materials research is experiencing major advances in both depth and breadth [1]. Flat bands, in particular, emerge in a diverse range of materials, spanning twisted heterostructures and compounds with geometrically frustrated lattices. They feature strong correlation effect alongside non-trivial topology. Recent experiments on active-flat-band kagome and pyrochlore metals have uncovered non-Fermi liquid behavior [2], while the discovery of superconductivity in TMD moiré systems has likewise generated much excitement. Here, we theoretically investigate the correlation phenomena in d-electron-based metals on frustrated lattices [3], and discuss the similarities and differences with the physics of TMD moiré systems [4]. The shared methodology we have developed is in terms of the notion of compact molecular orbitals, which enable effective models in the form of topological Kondo lattice models [3,4]. Accordingly, we advance the understanding of strange metallicity and unconventional superconductivity, while also suggesting a broader principle that topology induces quantum fluctuations and thus leads to new correlation physics. Together with the complementary advancements on Weyl-Kondo semimetals [5], these studies point toward a broader perspective that strong correlations and topology form a two-way road towards new states of quantum matter.
References:
[1] S. Paschen & Q. Si, Nat. Rev. Phys. 3, 9 (2021); H. Hu et al., Nat. Phys. 20, 1863 (2024).
[2] J. Huang et al., Nat. Phys. 20, 603 (2024); npj Quantum Mate 9, 71 (2024).
[3] J. C. Souza et al., Nat. Phys. 22, 541 (2026); L. Chen et al., Nat. Comm. 15, 5242 (2024); L. Chen et al., arXiv:2307.09431; H. Hu et al., Sci. Adv. 9, eadg0028 (2023); F. Xie et al., Phys. Rev. Res. 7, L022061 (2025).
[4] F. Xie et al., Phys. Rev. Lett. 134, 136503 (2025); C. Li et al., arXiv:2507.21043
[5] H.-H. Lai et al., PNAS 115, 93 (2018); H. Hu et al., arXiv:2110.06182; D. M. Kirschbaum, L. Chen et al., Nat. Phys. 22, 218 (2026)