Depletion of density of states near Fermi energy induced by disorder and electron correlation in alloys

TL;DR

This study investigates how disorder and electron correlation in alloys lead to a depletion of the density of states near the Fermi energy, confirmed through high-resolution photoemission experiments.

Contribution

It provides experimental evidence supporting the Altshuler-Aronov model predicting density of states depletion due to combined disorder and electron correlation in alloys.

Findings

Dips at the Fermi level observed in high-res photoemission spectra.

Depletion correlates with high residual resistivity and strong electron-electron interactions.

Results support the theoretical model of density of states suppression.

Abstract

We have performed high resolution photoemission study of substitutionally disordered alloys Cu-Pt, Cu-Pd, Cu-Ni, and Pd-Pt. The ratios between alloy spectra and pure metal spectra are found to have dips at the Fermi level when the residual resistivity is high and when rather strong repulsive electron-electron interaction is expected. This is in accordance with Altshuler and Aronov's model which predicts depletion of density of states at the Fermi level when both disorder and electron correlation are present.