Low-temperature conductivity of quasi-one-dimensional conductors: Luttinger liquid stabilized by impurities

TL;DR

This paper proposes a new stable non-Fermi-liquid state in quasi-one-dimensional conductors, where impurities stabilize bounded Luttinger liquids, leading to unique low-temperature conductivity behavior explained by phonon-assisted hopping and collective excitations.

Contribution

It introduces a novel state of matter where impurities stabilize Luttinger liquids, affecting electronic spectrum and conductivity in quasi-one-dimensional conductors.

Findings

Stability of the Luttinger liquid state against interchain hopping at low temperatures.

Presence of zero modes and Coulomb gap in the density of states.

Power-law voltage dependence of conductivity at higher voltages.

Abstract

A new non-Fermi-liquid state of quasi-one-dimensional conductors is suggested in which electronic system exists in a form of collection of bounded Luttinger liquids stabilized by impurities. This state is shown to be stable towards interchain electron hopping at low temperatures. Electronic spectrum of the system contains zero modes and collective excitations of the bounded Luttinger liquids in the segments between impurities. Zero modes give rise to randomly distributed localized electronic levels, and long-range interaction generates the Coulomb gap in the density of states at the Fermi energy. Mechanism of conductivity at low temperatures is phonon-assisted hopping via zero-mode states. At higher voltages the excitations of Luttinger liquid are involved in electron transport, and conductivity obeys power-law dependence on voltage. The results provide a qualitative explanation for recent experimental data for NbSe3 and TaS3 crystals.