Properties of Fluctuations in Two Coupled Chains of Luttinger Liquids

TL;DR

This paper investigates how coupling two Luttinger liquid chains affects their electronic properties, revealing the impact of interchain hopping and interactions on charge and spin fluctuations.

Contribution

It provides a detailed analysis of the effects of interchain coupling on the degeneracy and excitation spectrum of coupled Luttinger liquids.

Findings

Transverse charge density fluctuations become fully gapped.

Spin density excitations exhibit both gapped and gapless modes.

Interchain hopping significantly alters susceptibilities and electronic behavior.

Abstract

Two chains of Luttinger liquids coupled by both interchain hopping and interchain interaction are investigated. A degeneracy of two kinds of dominant states with in phase and out of phase ordering in the absence of the hopping is removed since the transverse fluctuation of charge density is completely gapful and that of spin density has two kinds of excitation with and without gap. The crucial effect of the interchain hopping on the electronic properties is studied by calculating susceptibilities.