Role of CDW fluctuations on the spectral function in a metallic CDW system

TL;DR

This study uses ARPES to investigate how charge-density-wave fluctuations influence the spectral function in ZrTe3, revealing pseudogap formation and coherence effects related to the dimensionality of Fermi surface sheets.

Contribution

It provides new insights into the impact of CDW fluctuations on spectral properties across different Fermi surface dimensionalities in a metallic CDW system.

Findings

Pseudogap forms on quasi 1D Fermi surface at temperatures above T_cdw.

Coherence increases at the van-Hove singularity where 1D and 3D Fermi surfaces intersect.

Spectral function effects are strongly linked to the dimensionality of electronic states.

Abstract

Angle-resolved photoemission spectroscopy of ZrTe3 has been performed from room temperature(T) down to 6 K (across Tcdw = 63K) to study the charge-density-wave (CDW) fluctuation effects in a metallic CDW compound having Fermi surface (FS) sheets with differing dimensionality. While spectra on the 3-dimensional(D) FS show typical Fermi-Dirac function-like T-dependence, those along the quasi 1-D FS show formation of a pseudogap, starting at a much higher T than Tcdw. Simultaneously, a van-Hove singularity consisting of the quasi 1D FS intersecting the 3D FS shows increase of coherence. This demonstrates the role of CDW fluctuations on the spectral function, and relation to the dimensionality of the states, in a metallic CDW system.