Impurity pinning in transport through 1D Mott-Hubbard and spin gap insulators

TL;DR

This paper investigates how impurities affect electron transport in one-dimensional Mott-Hubbard insulators and spin-gapped systems, revealing zero-energy resonances and duality in backscattered and direct currents.

Contribution

It introduces a detailed analysis of impurity pinning effects on transport in 1D Mott-Hubbard and spin gap insulators, highlighting the conditions for zero-energy resonances.

Findings

Conductance exhibits a zero-energy resonance under specific conditions.

Impurity pinning significantly influences transport properties.

Duality between backscattered current and direct current is established.

Abstract

A low energy crossover (see cond-mat/9711167) induced by Fermi liquid reservoirs in transport through a 1D Mott-Hubbard insulator of finite length $L$ is examined in the presence of impurity pinning. Under the assumption that the Hubbard gap 2M is large enough: $M > T_L \equiv v_c/L$ ($v_c$: charge velocity in the wire) and the impurity backscattering rate $\Gamma_1 \ll T_L$, the conductance vs. voltage/temperature displays a zero-energy resonance. Transport through a spin gapped 1D system is also described availing of duality between the backscattered current of this system and the direct current of the Mott-Hubbard insulator.