Dimensional Crossover in a Charge Density Wave Material Probed by Angle-Resolved Photoemission Spectroscopy

TL;DR

This study uses high-resolution ARPES to investigate a charge density wave material, NbSe3, revealing a temperature-dependent crossover from 1D to 3D electronic behavior and providing insights into the dimensionality of excitations.

Contribution

It demonstrates the dimensional crossover in NbSe3 through ARPES, linking spectral features to temperature-dependent electronic dimensionality changes.

Findings

Observation of 3D gaps due to CDWs at low temperatures

Spectral weight depletion approaching 1D power-law behavior at high temperatures

Extraction of the energy scale for the dimensional crossover from Fermi surface warping

Abstract

High-resolution angle-resolved photoemission spectroscopy (ARPES) data reveal evidence of a crossover from one-dimensional (1D) to three-dimensional (3D) behavior in the prototypical charge density wave (CDW) material NbSe3. In the low-temperature 3D regime, gaps in the electronic structure are observed due to two incommensurate CDWs, in agreement with x-ray diffraction and electronic-structure calculations. At higher temperatures we observe a spectral weight depletion that approaches the power-law behavior expected in 1D. From the warping of the quasi-1D Fermi surface at low temperatures, we extract the energy scale of the dimensional crossover. This is corroborated by a detailed analysis of the density of states, which reveals a change in dimensional behavior dependent on binding energy. Our results offer an important insight into the dimensionality of excitations in quasi-1D materials.