Quasi-Particle Spectra, Charge-Density-Wave, Superconductivity and Electron-Phonon Coupling in 2H-NbSe2

TL;DR

This study uses high-resolution photoemission to analyze the electronic structure and quasiparticle interactions in 2H-NbSe2, revealing strong, anisotropic electron-phonon coupling and minimal impact of the charge density wave transition.

Contribution

It provides detailed insights into the quasiparticle interactions and electron-phonon coupling in 2H-NbSe2, highlighting differences from similar materials like TaSe2.

Findings

Electron-phonon coupling is the dominant quasiparticle interaction.

Charge density wave transition has little effect on electronic properties.

Electron-phonon coupling is highly anisotropic and stronger than in TaSe2.

Abstract

High-resolution photoemission has been used to study the electronic structure of the charge density wave (CDW) and superconducting (SC) dichalcogenide, 2H- NbSe2. From the extracted self-energies, important components of the quasiparticle (QP) interactions have been identified. In contrast to previously studied TaSe2, the CDW transition does not affect the electronic properties significantly. The electron-phonon coupling is identified as a dominant contribution to the QP self-energy and is shown to be very anisotropic (k-dependent) and much stronger than in TaSe2.