Three-dimensional Fermi surface of 2H-NbSe$_2$ - Implications for the mechanism of charge density waves

TL;DR

This study uses experimental and theoretical methods to reveal the three-dimensional electronic structure of 2H-NbSe$_2$, showing that its 3D character influences the understanding of charge density wave mechanisms and their competition with superconductivity.

Contribution

The paper provides the first detailed analysis combining soft x-ray ARPES and DFT to characterize the 3D electronic structure of 2H-NbSe$_2$, challenging the nesting-driven CDW formation hypothesis.

Findings

Pronounced 3D character of the electronic structure.

Strong dispersion along $k_z$, inconsistent with nesting-driven CDW.

Implications for phase competition between CDW and superconductivity.

Abstract

We investigate the three-dimensional electronic structure of the seminal charge-density-wave (CDW) material 2H-NbSe$_2$ by soft x-ray angle-resolved photoelectron spectroscopy and density-functional theory. Our results reveal the pronounced 3D character of the electronic structure formed in the quasi-two-dimensional layered crystal structure. In particular, we find a strong dispersion along $k_z$ excluding a nesting-driven CDW formation based on experimental data. The 3D-like band structure of 2H-NbSe$_2$ has strong implications for the intriguing phase competition of CDW order with superconductivity.