Fermi surface nesting in several transition metal dichalcogenides

Abstract

By means of high-resolution angle resolved photoelectron spectroscopy (ARPES) we have studied the fermiology of 2H transition metal dichalcogenide polytypes TaSe2, NbSe2, and Cu0.2NbS2. The tight-binding model of the electronic structure, extracted from ARPES spectra for all three compounds, was used to calculate the Lindhard function (bare spin susceptibility), which reflects the propensity to charge density wave (CDW) instabilities observed in TaSe2 and NbSe2. We show that though the Fermi surfaces of all three compounds possess an incommensurate nesting vector in the close vicinity of the CDW wave vector, the nesting and ordering wave vectors do not exactly coincide, and there is no direct relationship between the magnitude of the susceptibility at the nesting vector and the CDW transition temperature. The nesting vector persists across the incommensurate CDW transition in TaSe2 as a function of temperature despite the observable variations of the Fermi surface geometry in this temperature range. In Cu0.2NbS2 the nesting vector is present despite different doping level, which lets us expect a possible enhancement of the CDW instability with Cu-intercalation in the CuxNbS2 family of materials.

Accepted to New J. Phys

References in corpus (3)

• The Ground State of the Pseudogap in Cuprate Superconductors
• Quasi-Particle Spectra, Charge-Density-Wave, Superconductivity and Electron-Phonon Coupling in 2H-NbSe2
• Non-uniform doping across the Fermi surface of NbS${}_2$ intercalates

Cited by in corpus (3)

• Momentum-resolved superconducting gap in the bulk of Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$ from combined ARPES and $\mu$SR measurements
• Electronic structure and nesting-driven enhancement of the RKKY interaction at the magnetic ordering propagation vector in Gd2PdSi3 and Tb2PdSi3
• Temperature-dependent Fermi surface of 2H-TaSe2 driven by competing density wave order fluctuations