A variational method in the problem of screening an external charge in strongly correlated metals

TL;DR

This paper presents a variational approach to model how a point charge is screened in layered strongly correlated metals near the Mott transition, revealing nonlinear effects and local incompressibility.

Contribution

It introduces a variational method to analyze nonlinear screening and local incompressibility in layered correlated metals close to the Mott transition.

Findings

External charge induces locally incompressible regions.

Nonlinear screening can cause overscreening in nearby layers.

Overall charge neutrality is maintained.

Abstract

We describe a variational calculation for the problem of screening of a point charge in a layered correlated metal for dopings close to the Mott transition where the screening is non-linear due to the proximity to the incompressible insulating state. We find that external charge can induce locally incompressible regions and that the non-linear dependence of the screening on density can induce overscreening in the nearest nearby layers while preserving overall charge neutrality.