Multiorbital two-band Landau–Fermi liquidness of 1T-Ti(Se,Te)2 van der Waals crystals

Craco, Luis, Hou, Bo ORCID: https://orcid.org/0000-0001-9918-8223 and Leoni, Stefano ORCID: https://orcid.org/0000-0003-4078-1000 2026. Multiorbital two-band Landau–Fermi liquidness of 1T-Ti(Se,Te)2 van der Waals crystals. Inorganic Chemistry 10.1021/acs.inorgchem.5c04404

PDF - Published Version Available under License Creative Commons Attribution. Download (4MB)

Abstract

Normal-state Landau–Fermi-liquid (LFL) behavior is widely regarded as a prerequisite for low-temperature superconductivity in 1T-TiX2 (X = Se, Te) van der Waals (vdW) crystals. Clarifying this role requires a microscopic description of how local electron correlations and Ti–chalcogen covalence cooperate to shape the low-energy electronic structure in the noncharge-density-wave (non-CDW) regime. In the present work, we employ density functional theory combined with dynamical mean-field theory (DFT + DMFT) to investigate an extended multiorbital (MO) two-band Hubbard model specifically constructed for these transition-metal dichalcogenides. The calculations reveal an emergent LFL metal stabilized by dynamical intra- and interorbital correlations in the Ti-based manifold, while the chalcogen 4p/5p states remain comparatively rigid against changes in interaction strength. This orbital-selective reconstruction leads to a strongly anisotropic renormalization of the Ti-3d sector, which we identify as a key ingredient for the superconducting phase diagram of 1T-TiX2. Beyond demonstrating the capability of DFT + DMFT to capture such MO correlation effects, our results show that proximity to a correlated LFL state naturally accounts for the distinct low-temperature transport responses of the Se and Te compounds, where modest variations in interaction-to-bandwidth ratio and orbital occupancy drive markedly different sensitivities to external tuning parameters such as pressure, doping, or gating.

Item Type:	Article
Date Type:	Publication
Status:	In Press
Schools:	Schools > Chemistry Schools > Physics and Astronomy
Publisher:	American Chemical Society
ISSN:	0020-1669
Date of First Compliant Deposit:	9 February 2026
Date of Acceptance:	9 January 2026
Last Modified:	09 Feb 2026 15:30
URI:	https://orca.cardiff.ac.uk/id/eprint/184560

Actions (repository staff only)

Edit Item