Electron transport in coupled chains of interacting fermions with impurities

TL;DR

This paper investigates how electron transport in a two-chain fermion system is affected by interactions and impurities, revealing conditions for conductance suppression or perfect transmission, and explaining resistivity behavior.

Contribution

It provides new insights into transport phenomena in coupled fermionic chains with impurities, highlighting the role of interactions and barriers in conductance behavior.

Findings

Conductance is suppressed above a certain interaction strength.

Perfect transmission occurs in a specific repulsive interaction region.

Explains the temperature maximum of resistivity in normal state of ext{srca}.

Abstract

We study the low-temperature transport of a doped two-chain ladder system of interacting fermions in the presence of a barrier or of a low concentration of impurities. Above a certain value of the interaction, the conductance is suppressed, like for a single chain, despite the presence of dominant superconducting correlations. There is, however, a region of repulsive interaction where perfect transmission across the barrier occurs unlike the single-chain case. We provide a possible explanation for the temperature maximum of the resistivity in the normal state of \srca.