Effect of impurity pinning on conduction and specific heat in the Luttinger liquid

TL;DR

This paper explores impurity effects on conduction and specific heat in 1D Luttinger liquids, revealing a new conduction regime with oscillations and a magnetic field dependence of specific heat akin to CDW materials.

Contribution

It introduces a theoretical analysis of impurity pinning effects on electron transport and specific heat in Luttinger liquids, highlighting a novel conduction regime and magnetic field dependence.

Findings

DC current oscillations with frequency f=I/e in the new conduction regime

Magnetic field dependence of specific heat similar to CDW compounds

Impurity pinning influences both conduction and thermodynamic properties

Abstract

We study theoretically two effects related to impurity depinning that are common for 1D Luttinger liquid (LL) and linear-chain CDW conductors. First, we consider the electron transport through a single impurity in a 1D conducting channel and study a new regime of conduction related to LL sliding at voltage above a threshold one. The DC current in this regime is accompanied by oscillations with frequency $f =I/e$. This resembles the CDW depinning in linear-chain conductors, the Josephson effect, and the Coulomb blockade. Second, we found that strong pinning of the LL by impurities leads to a magnetic field dependence of the low-temperature specific heat similar to that observed experimentally in CDW compounds. We interpret this in favor of possibility of formation of the LL in linear-chain compounds.