Flat modes and phonon anomalies in twisted kagome lattice

Metallic kagome systems have raised in the recent years as a new type of materials hosting topological flat bands, Dirac crossings and van Hove singularities that give rise to intertwined charge density waves (CDW), magnetism and superconductivity. In this proposal, we want to measure the low energy phonon spectra associated with the single-qCDW in the twisted bilayer kagome net YCo6Ge6. We intend to comprehensively measure the temperature and momentum dependence of the low energy acoustic and optical phonons by means of high-resolution inelastic x-ray scattering (IXS). Our preliminary diffuse scattering data detected precursors located in the plane with odd L=1, 3, 5 that might be related to the critical role of chemical bond instability, phonon softening or the order-disorder character of the pre-translational fluctuations.