Correlation-enhanced Friedel oscillations in amorphous and quasicrystalline metals

Johann Kroha

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arXiv · cond-mat/9707295

Correlation-enhanced Friedel oscillations in amorphous and quasicrystalline metals

Johann Kroha

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Abstract

The exponentially strong damping of the conventional Friedel oscillations at elevated temperature T as well as due to disorder poses a severe problem to the Hume-Rothery (HR) stabilization mechanism of amorphous and quasicrystalline alloys. We show that quantum correlations induced by electron-electron interactions in the presence of random impurity scattering can play an important role in stabilizing these systems: When there is strong backscattering off local ion clusters, the static electron density response chi(0,q) acquires a powerlaw divergence at q=2k_F even at T>0. This Fermi surface singularity leads to an enhancement as well as to a systematical phase shift of the Friedel oscillations, consistent with experiments. In addition, the spatial decay exponent is reduced, strongly supporting the validity of a HR-like mechanism at T>0. This effect may be accounted for in pseudopotential calculations through the local field factor.

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Johann Kroha. 1997-07-29. Correlation-enhanced Friedel oscillations in amorphous and quasicrystalline metals. https://arxiv.org/abs/cond-mat/9707295

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