Friedel oscillations of Density of States in a one-dimensional Mott insulator and Incommensurate Charge Density Wave/Superconductor

TL;DR

This paper calculates how a single impurity causes oscillations in the local density of states in one-dimensional systems with charge or spin gaps, revealing characteristic wave vectors and frequency-dependent amplitude peaks.

Contribution

It provides a detailed theoretical analysis of impurity-induced Friedel oscillations in 1D Mott insulators and incommensurate charge density wave/superconductor systems, highlighting their spectral features.

Findings

Oscillations occur at wave vectors π (Mott insulator) and 2k_F (ICDW/SC).

Oscillation amplitude peaks near three times the spectral gap m.

Finite frequency oscillations develop above the gap.

Abstract

Oscillations of local density of states generated by a single scalar impurity potential are calculated for one-dimensional systems with dynamically generated charge or spin gap. At zero temperature the oscillations develop at finite wave vector ($\pi$ for the Mott insulator and $2k_F$ for ICDW/SC) and at frequencies larger than the soliton spectral gap $m$. Their amplitude has a broad maximum at $\omega \approx 3m$, where $m$ is the gap magnitude.