Laboratoire Léon Brillouin

UMR12 CEA-CNRS, Bât. 563 CEA Saclay

91191 Gif sur Yvette Cedex, France


BD diffusons les neutrons

CDWs and phonon anomalies in kagome metals
Santiago Blanco Canosa
Donostia International Physics Center, San Sebastian, Spain
Jeudi 01/02/2024, 11:00-12:01
LLB - Bât 563 p15 (Grande Salle), CEA-Saclay

The long range electronic modulations recently discovered in the geometrically frustrated kagome lattice have opened new avenues to explore the effect of correlations in materials with topological electron flat bands [1]. In this talk, I will present ARPES, diffuse scattering and inelastic x-ray scattering (IXS) data in several kagome metals that allow a comprehensive study their phase transitions. I will focus on the recently discovered multiple-q charge modulations in (Cs,Rb)V3Sb5 [2], FeGe [3]and ScV6Sn6 [4] and explain how their dynamics follow either an order-disorder scenario common in first order phase transformations or a phonon softening characteristic of a second order phase transition. Furthermore, I will show the potential of diffuse scattering to identify primary order parameters and its coupling/competition to secondary orders in the study of multiple-q charge density waves in materials hosting correlated flat phonon-topological flat electron physics.


Figure 1: Momentum dependence of the 1/3 1/3 13/2 phonon frequency at selected temperatures, highlighting the large momentum softening in ScV6Sn6.



[1] B. R. Ortiz et al., Phys. Rev. Materials 3, 094407 (2018).
[2] D. Subires et al., Nat. Comm. 14, 1015 (2023)
[3] D. Subires et al., in preparation
[4] A. Korshunov et al., Nature Comm. 14, 6646 (2023).
Contact : Alain MENELLE

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