Spectral properties of Luttinger liquids: A comparative analysis of regular, helical, and spiral Luttinger liquids

TL;DR

This paper analytically compares the spectral properties of various Luttinger liquids, including regular, helical, and spiral types, revealing distinct responses and providing explicit Green's functions and density of states expressions.

Contribution

It offers the first comprehensive analytic expressions for Green's functions and tunneling density of states across multiple Luttinger liquid types, including the newly distinguished spiral Luttinger liquid.

Findings

Different response functions for spiral versus helical Luttinger liquids.

Explicit analytic formulas for Green's functions and density of states.

Spiral Luttinger liquids exhibit significantly different spectral properties.

Abstract

We provide analytic expressions for the Green's functions in position-frequency space as well as for the tunneling density of states of various Luttinger liquids at zero temperature: the standard spinless and spinful Luttinger liquids, the helical Luttinger liquid at the edge of a topological insulator, and the Luttinger liquid that appears either together with an ordering transition of nuclear spins in a one-dimensional conductor, or in spin-orbit split quantum wires in an external magnetic field. The latter system is often used to mimic a helical Luttinger liquid, yet we show here that it exhibits significantly different response functions and, to discriminate, we call it the spiral Luttinger liquid. We give fully analytic results for the tunneling density of state of all the Luttinger liquids as well as for most of the Green's functions. The remaining Green's functions are expressed by simple convolution integrals between analytic results.