Gate-tunable heavy fermion quantum criticality in a moir\'e Kondo lattice

TL;DR

This paper proposes a moiré superlattice system where gate-tunable Kondo interactions induce a quantum phase transition between a heavy-fermion state and a chiral spin-liquid, revealing new avenues for quantum criticality in 2D materials.

Contribution

It introduces a novel moiré heterostructure platform to realize and study gate-tunable heavy fermion quantum criticality and fractionalized phases.

Findings

Identification of a gate-tunable quantum phase transition in the proposed system.

Prediction of experimental signatures distinguishing different quantum phases.

Demonstration of a range of twist-angles supporting the quantum critical behavior.

Abstract

We propose a realization of Kondo-lattice physics in moir\'e superlattices at the interface between a WX$_2$ homobilayer and MoX$_2$ monolayer (where X=S,Se). Under appropriate gating conditions, the interface-WX$_2$-layer forms a triangular lattice of local moments that couple to itinerant electrons in the other WX$_2$-layer via a gate-tunable Kondo exchange interaction. Using a parton mean-field approach we identify a range of twist-angles which support a gate-tuned quantum phase transition between a heavy-fermion liquid with large anomalous Hall conductance and a fractionalized chiral spin-liquid coexisting with a light Fermi liquid, and describe experimental signatures to distinguish among competing theoretical scenarios.