Spectral properties of one dimensional insulators and superconductors

TL;DR

This paper uses conformal field theory and Bethe ansatz to analyze the spectral functions of one-dimensional insulators and superconductors, revealing exotic behaviors and confirming predictions with numerical methods, relevant for experimental observations.

Contribution

It introduces a combined theoretical approach to study spectral properties in 1D systems, highlighting momentum-dependent exponents in superconductors and validating results with numerical diagonalizations.

Findings

Exotic momentum-dependent Luttinger Liquid exponents in superconductors

Confirmation of theoretical predictions via Lanczos diagonalizations

Relevance to photoemission experiments in quasi-1D materials

Abstract

Conformal field theory and Bethe ansatz are used to investigate the low energy features of the spectral function in one dimensional models which exhibit a gap in the spin or in the charge excitation spectrum. Exotic behavior is found in the superconducting case, where the Green function displays momentum dependent Luttinger Liquid exponents. The predictions of the formalism are confirmed by Lanczos diagonalizations in the $tJ$ model up to 32 sites. These results may be relevant in connection to photoemission experiments in quasi one dimensional insulators or superconductors.