Kondo proximity effect: How does a metal penetrate into a Mott insulator?

TL;DR

This paper explores how a metallic state penetrates a Mott insulator through the Kondo effect, analyzing the interface's scaling behavior near the Mott transition using advanced theoretical methods.

Contribution

It introduces a detailed mean field analysis of the metal-insulator interface, revealing the power-law decay of quasiparticle weight at criticality and quantifying the Kondo proximity effect.

Findings

Quasiparticle weight decays as 1/x^2 near the interface.

The prefactor of the decay is extremely small.

The study uses dynamical mean field theory and numerical renormalization group methods.

Abstract

We consider a heterostructure of a metal and a paramagnetic Mott insulator using an adaptation of dynamical mean field theory to describe inhomogeneous systems. The metal can penetrate into the insulator via the Kondo effect. We investigate the scaling properties of the metal-insulator interface close to the critical point of the Mott insulator. At criticality, the quasiparticle weight decays as 1/x^2 with distance x from the metal within our mean field theory. Our numerical results (using the numerical renormalization group as an impurity solver) show that the prefactor of this power law is extremely small.