Localizations in coupled electronic chains

TL;DR

This paper investigates how electron-electron interactions and random potentials influence localization and charge stiffness in coupled Hubbard chains, revealing that interactions can extend localization length and counteract disorder effects.

Contribution

It provides a renormalization group analysis of localization in coupled Hubbard chains, highlighting the role of interactions in modifying localization length and charge stiffness.

Findings

Localization length scales with the number of chains for non-interacting electrons.

Stronger interactions increase localization length, especially in single chains.

Interactions reduce the impact of random potentials on charge stiffness.

Abstract

We studied effects of random potentials and roles of electron-electron interactions in the gapless phase of coupled Hubbard chains, using a renormalization group technique. For non-interacting electrons, we obtained the localization length proportional to the number of chains, as already shown in the other approaches. For interacting electrons, the localization length is longer for stronger interactions, that is, the interactions counteract the random potentials. Accordingly, the localization length is not a simple linear function of the number of chains. This interaction effect is strongest when there is only a single chain. We also calculate the effects of interactions and random potentials on charge stiffness.