# Quasi one-dimensional metallic band dispersion in the commensurate charge density wave of $1T$-TaS$_2$

## TL;DR

This study reveals that the commensurate charge density wave in 1T-TaS2 exhibits a quasi-one-dimensional metallic band, confirmed through experimental ARPES measurements, aligning with recent theoretical predictions.

## Contribution

The paper provides experimental evidence for a predicted quasi-one-dimensional metallic band in 1T-TaS2's CDW state, challenging the view of it as purely two-dimensional.

## Key findings

- Existence of a metallic band with one-dimensional dispersion
- Band width matches predictions for a specific stacking order
- Periodicity in the c direction is 2π/c

## Abstract

The commensurate charge density wave (CDW) in the layered compound $1T$-TaS$_2$ has hitherto mostly been treated as a quasi two-dimensional phenomenon. Recent band structure calculations have, however, predicted that the CDW coexists with a nearly one-dimensional metallic dispersion perpendicular to the crystal planes. Using synchrotron radiation based angle-resolved photoemission spectroscopy, we show that this metallic band does in fact exist. Its occupied band width is in excellent agreement with predictions for a simple $\tau_c$ stacking order of the CDW between adjacent layers and its periodicity in the $c$ direction is $2 \pi / c$.