Electronic stabilization of amorphous and quasicrystalline metals: Importance of quantum correlations

Abstract

Numerous experimental indications suggest that the Hume-Rothery mechanism plays an important role in stabilizing quasicrystalline and amorphous phases. However, the exponential damping of the conventional Friedel oscillations at the relevant, elevated temperatures $T$ poses a severe challenge to the HR stabilization. In order to resolve this problem it is shown using a Feynman diagram technique that quantum correlations in the electron sea, arising from the interplay of Coulomb interaction and impurity scattering, can strongly enhance the Friedel oscillations in these systems even at elevated temperature. The resulting corrections to the Friedel potential are in agreement with available experimental results on amorphous HR alloys. It is proposed to include the enhancement of the Friedel amplitude derived in the present work into pseudopotentials through the local field factor.