Quantum critical Mott transitions in a bilayer Kondo insulator-metal model system

TL;DR

This paper investigates quantum critical Mott transitions in a bilayer Kondo insulator-metal system using dynamical mean field theory, revealing a surface of quantum critical points with complete Fermi surface destruction.

Contribution

It introduces a bilayer KI-M model exhibiting a surface of quantum critical points with unique Fermi surface destruction, expanding understanding of Mott transitions.

Findings

Identification of a surface of quantum critical points separating distinct phases.

Complete Fermi surface destruction at the quantum critical points.

Characterization of the transition via vanishing coherence scale and Mott gap.

Abstract

A bilayer system comprising a Kondo insulator coupled to a simple metal (KI-M) is considered. Employing the framework of dynamical mean field theory, the model system is shown to exhibit a surface of quantum critical points (QCPs), that separates a Kondo screened, Fermi liquid phase from a local moment, Mott insulating phase. The quantum critical nature of these Mott transitions is characterized by the vanishing of (a) the coherence scale on the Fermi liquid side, and (b) the Mott gap on the MI side. In contrast to the usual `large to small' Fermi surface (FS) QCPs in heavy fermion systems, the bilayer KI-M system exhibits a complete FS destruction.