Pseudo-Quantum Criticality in Electron Liquids Exhibited in Expanded Alkali Metals

TL;DR

This paper investigates Coulombic screening and electronic polarization in alkali metals, revealing pseudo-quantum critical behavior linked to compressibility divergence, and predicts ion equilibration distance changes confirmed by experiments on liquid Rb.

Contribution

It introduces the concept of pseudo-quantum criticality in electron liquids and predicts ion behavior changes due to divergence in compressibility, supported by experimental data.

Findings

Singular long-range fluctuations in electronic polarization due to compressibility divergence.

Predicted decrease in ion-ion equilibration distance with increasing Wigner-Seitz radius.

Quantitative agreement with recent liquid Rb experiments.

Abstract

With paying special attention to the divergence in the compressibility $\kappa$, we study the Coulombic screening in alkali metals to find singular long-range fluctuations in the electronic polarization originating from this divergence. As a consequence of this singularity, we predict the decrease of the equilibration distance between ions against the increase of $r_s$ the Wigner-Seitz radius of valence electrons, provided that the condition of $2r_c < r_s < 4r_c$ is satisfied with $r_c$ the ion-core radius. This prediction is in good quantitative agreement with the recent experiment on liquid Rb.