Translation symmetry-breaking order is assumed to be suppressed by the lack of Fermi surface nesting near certain higher-order Van Hove singularities (HOVHS). We show the anisotropic band-flattening inherent to such HOVHS, combined with broadening of the Fermi surface due to elevated critical temperatures, results in the Fermi surface becoming approximately nested at a wavevector unrelated to the precise shape of the Fermi surface - leading to a 3×3 Kekul\'e density wave formation. The effect is demonstrated using unbiased renormalization group calculations for a model of the breathing kagome lattice. Our mechanism - termed diffuse nesting - represents an entirely new notion in the study of Fermi surface instabilities.
@article{arxiv.2505.22725,
title = {Kekul\'e order from diffuse nesting near higher-order Van Hove points},
author = {Jonas Beck and Jonathan Bodky and Matteo Dürrnagel and Ronny Thomale and Julian Ingham and Lennart Klebl and Hendrik Hohmann},
journal= {arXiv preprint arXiv:2505.22725},
year = {2026}
}