Transition from a Tomonaga-Luttinger liquid to a Fermi liquid in potassium intercalated bundles of single wall carbon nanotubes

TL;DR

This study demonstrates a transition from Tomonaga-Luttinger liquid to Fermi liquid behavior in potassium-doped single wall carbon nanotubes, highlighting the effects of doping on electronic properties.

Contribution

First direct observation of the transition from Tomonaga-Luttinger liquid to Fermi liquid in doped SWCNT bundles using photoemission spectroscopy.

Findings

Low doping shows Tomonaga-Luttinger liquid behavior.

High doping results in Fermi liquid behavior.

Transition linked to band filling and screening effects.

Abstract

We report on the first direct observation of a transition from a Tomonaga-Luttinger liquid to a Fermi liquid behavior in potassium intercalated mats of single wall carbon nanotubes (SWCNT). Using high resolution photoemission spectroscopy an analysis of the spectral shape near the Fermi level reveals a Tomonaga-Luttinger liquid power law scaling in the density of states for the pristine sample and for low dopant concentration. As soon as the doping is high enough to fill bands of the semiconducting tubes a distinct transition to a bundle of only metallic SWCNT with a scaling behavior of a normal Fermi liquid occurs. This can be explained by a strong screening of the Coulomb interaction between charge carriers and/or an increased hopping matrix element between the tubes.