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

We have performed high-resolution photoemission study of substitutionally disordered alloys Cu–Pt, 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 strong repulsive electron–electron interaction is expected. This is in accordance with Altshuler and Aronovʹs model which predicts a depletion of the density of states at the Fermi level when both disorder and electron correlation are present.