Power spectrum of many impurities in a d-wave superconductor

TL;DR

This paper investigates how multiple impurities in a d-wave superconductor affect the local density of states power spectrum, challenging previous interpretations of observed peaks as simple scattering features.

Contribution

It introduces analytical and numerical analysis showing impurity interference modifies the expected spectral peaks, offering new insights into the disorder potential in BSCCO.

Findings

Impurity interference alters the interpretation of spectral peaks.

Observed peaks are background structures dispersing with octet vectors.

Results constrain the form of the disorder potential in BSCCO.

Abstract

Recently the structure of the measured local density of states power spectrum of a small area of the \BSCCO (BSCCO) surface has been interpreted in terms of peaks at an "octet" of scattering wave vectors determined assuming weak, noninterfering scattering centers. Using analytical arguments and numerical solutions of the Bogoliubov-de Gennes equations, we discuss how the interference between many impurities in a d-wave superconductor alters this scenario. We propose that the peaks observed in the power spectrum are not the features identified in the simpler analyses, but rather "background" structures which disperse along with the octet vectors. We further consider how our results constrain the form of the actual disorder potential found in this material.