Pomeranchuk instability from electronic correlations in CsTi<sub>3</sub>Bi<sub>5</sub> kagome metal.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41436439.
- Also identified by DOI 10.1038/s41467-025-67037-4 and PMC identifier 12789546.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Electronic nematicity, the spontaneous breaking of rotational symmetry, has emerged as a key instability in correlated quantum systems. CsTi<sub>3</sub>Bi<sub>5</sub>, a kagome metal of the AV<sub>3</sub>Sb<sub>5</sub> (A = K, Rb, Cs) family, hosts rich unconventional electronic phases, yet the origin of its nematicity remains unsettled. Here, we combine polarization-dependent angle-resolved photoemission spectroscopy with functional renormalization group calculations on a fully interacting ab initio model. We reveal an orbital-selective nematic deformation in the low-energy band structure and identify a finite angular momentum (d-wave) Pomeranchuk instability driven by electronic correlations in specific orbital channels and detuning from Van Hove singularities. Our results establish a direct link between orbital selectivity and symmetry-breaking instabilities in CsTi<sub>3</sub>Bi<sub>5</sub>, providing a microscopic framework for nematic order in kagome systems.