2024/05/29 by Ludovica Zullo, Zullo, Ludovica, Grégory Setnikar +19
Materials Science · #Crystal Structures and Properties #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Organic and Molecular Conductors Research #Solid-state spectroscopy and crystallography
paper · pdf · doi:10.48550/arxiv.2405.18939
openalex publication_date 2024/05/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
Misfit layer compounds, heterostructures composed by a regular alternating stacking of rocksalt monochalcogenides bilayers and few-layer transition metal dichalchogenides, are an emergent platform to investigate highly doped transition metal dichalcogenides. Among them, (LaSe)1.14(NbSe2)2 displays Ising superconductivity, while the presence of a charge density wave (CDW) in the material is still under debate. Here, by using polarized Raman spectroscopy and first-principles calculations, we show that NbSe2 undergoes a doping-driven collapse of the CDW ordering within the misfit, and no signature of the CDW is detected down to 8~K. We provide a complete experimental and theoretical description of the lattice dynamics of this misfit compound. We show that the vibrational properties are obtained from those of the two subunits, namely the LaSe unit and the NbSe2 bilayer, in the presence of a suitable field-effect doping, and then highlight the 2D nature of the lattice dynamics of NbSe2 within the (LaSe)1.14(NbSe2)2 3D structure.