Dynamics and Resilience of the Charge Density Wave in a bilayer kagome metal

• DOI: 10.48550/arxiv.2302.10699
• Publication Date: 2023-01-01
• Authors: Manuel Tuniz; Armando Consiglio; Denny Puntel; Chiara Bigi; Stefan Enzner; Ganesh Pokharel; P. Orgiani; Wibke Bronsch; F. Parmigiani; Vincent Polewczyk; P. D. C. King; Justin W. Wells; Ilija Zeljkovic; Pietro Carrara; G. Rossi; Jun Fujii; I. Vobornik; Stephen D. Wilson; Ronny Thomale; Tim O. Wehling; Giorgio Sangiovanni; G. Panaccione; Federico Cilento; Domenico Di Sante; Federico Mazzola
• Keywords: Van Hove singularity; Charge Density Wave; Density of states; Bilayer graphene; Charge density

Long-range electronic order descending from a metallic parent state constitutes rich playground to study the intricate interplay of structural and degrees freedom. With dispersive correlation features as multifold topological Dirac-like itinerant states, van-Hove singularities, correlated flat bands, magnetic transitions at low temperature, kagome metals are located in most interesting regime where both phonon electronically mediated couplings significant. Several these systems undergo charge density wave (CDW) transition, which intrinsic tiling, have been conjectured play key role mediating such an instability. However, date, origin main driving force behind this is elusive. Here, we use bilayer metal ScV6Sn6 platform investigate puzzling problem, since it kagome-derived nested Fermi surface singularities near level, CDW phase that affects susceptibility, neutron scattering, specific heat, similarly siblings AV3Sb5 (A = K, Rb, Cs) FeGe. We report on our findings high-resolution angle-resolved photoemission, functional theory, time-resolved optical spectroscopy unveil dynamics its phase. identify freedom fundamental stabilization order. Along with comprehensive analysis subdominant impact correlations, find feature instance predominantly originates phonons. As shed light emergent profile low-temperature ordered regime, pave way for deeper understanding ordering phenomena all metals.