Persistent current of two-chain Hubbard model with impurities

TL;DR

This paper investigates how impurities and electron interactions affect persistent currents in a two-chain Hubbard model, revealing that interactions have a reduced impact compared to a single-chain system.

Contribution

It provides a detailed analysis of impurity screening and persistent current behavior in a two-chain Hubbard model, extending understanding beyond single-chain models.

Findings

Interactions less enhance charge stiffness than in single-chain models

Impurities' effects are modified by the multi-channel structure

Persistent current behavior differs from single-chain predictions

Abstract

The interplay between impurities and interactions is studied in the gapless phase of two-chain Hubbard model in order to see how the screening of impurity potentials due to repulsive interactions in single-chain model will be changed by increasing the number of channels. Renormalization group calculations show that charge stiffness, and hence persistent current, of the two-chain model are less enhanced by interactions than single chain case.