Tuning Superconductivity and Charge Density Wave Order in 2H-TaSe2 by Modulating the Van Hove Singularity

Abstract

Tantalum diselenide (TaSe2) is an exciting material that hosts charge density wave order (CDW) and superconductivity. Thus, providing a playing field for examining the interactions of fundamental electronic quantum states in materials. Recent research has proposed that the intrinsic quantum electronic state in the TaSe2 lattice could be improved by aligning the Van Hove singularity (VHs) with the Fermi level. In this study, we attempt to tune the VHs in TaSe2 to align them within the vicinity of the Fermi level via electron doping by chemically substituting Pt for Ta atoms. On investigating the band structure of Pt0.2Ta0.8Se2, the electron doping brought the VHs closer to the Fermi level vicinity around the K high symmetry point. As a result, the CDW state in pristine TaSe2 is suppressed in the TaSe2 doped system while also hosting an enhanced superconducting temperature (Tc) of ~2.7 K. These observations provide insight into ways to leverage the VHs in materials to tune their electronic properties.

14 pages, 4 figures

References in corpus (11)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Charge density waves and electronic properties of superconducting kagome metals
• Unusual competition of superconductivity and charge-density-wave state in a compressed topological kagome metal
• Emergence of new van Hove singularities in the charge density wave state of a topological kagome metal RbV3Sb5
• Fermi surface nesting in several transition metal dichalcogenides
• Tuning the van Hove singularities in AV${}_3$Sb${}_5$ (A = K, Rb, Cs) via pressure and doping
• Coexisting charge density wave and ferromagnetic instabilities in monolayer InSe
• Alternating superconducting and charge density wave monolayers within bulk 6R-TaS2
• Saddle-point van Hove singularity and the phase diagram of high-Tc cuprates
• Charge density wave and superconductivity competition in Lu${}_5$Ir${}_4$Si${}_{10}$ : a proton irradiation study
• Effect of Van Hove singularities on Shiba states in two-dimensional $s$-wave superconductors

Cited by in corpus (2)

• Charge Orders in Fully Intercalated Bilayer TaSe${}_2$: Dependence on Interlayer Stacking and Intercalation Sites
• Superconducting Sn-Intercalated TaSe${}_2$: Structural Diversity Obscured by Routine Characterization Techniques