Transport through a 1D Mott-Hubbard insulator of finite length

TL;DR

This paper investigates electron transport in a finite-length 1D Mott-Hubbard insulator, revealing how strong interactions suppress conductance near half-filling except in exponentially small regions at low voltage and temperature.

Contribution

It maps the complex transport problem onto exactly solvable models at specific interaction parameters, providing explicit current-voltage characteristics beyond perturbation theory.

Findings

Transport is suppressed near half-filling for large Mott-Hubbard gaps.

At high temperature, the model's behavior is characterized for specific energy regimes.

Low-energy transport is exponentially suppressed within the gap.

Abstract

Transport through a 1D Mott-Hubbard insulator of a finite length $L$ is studied beyond perturbative approach. At special value of the low energy constant of the interaction we have mapped the problem onto the exactly solvable models and found current vs. voltage $V$ at high temperature $T>max(m,T_L)$ and at low energy $T,V<T_L$ ($T_L=v_c/L$; $v_c:$ charge velocity). The result shows that for the strong interaction creating a large Mott-Hubbard gap $2m \gg T_L $ inside the wire, the transport is suppressed near half-filling everywhere inside the gap except for an exponentially small region of $V,T < T_L exp(-2m/T_L)$.