Gate-defined Kondo lattices with valley-helical quantum dot arrays

TL;DR

This paper proposes gate-defined superlattices in Bernal bilayer graphene that enable tunable Kondo physics and heavy-fermion behavior, overcoming disorder issues in moiré materials.

Contribution

It introduces device layouts for gate-defined Kondo lattices in bilayer graphene, allowing in-situ control of phase diagrams without twisting angle disorder.

Findings

Superlattices described by an electrically-tunable Kondo-Heisenberg model.

Localized states couple to valley-helical modes in the proposed devices.

Potential for studying Kondo physics in a highly controllable platform.

Abstract

Kondo physics and heavy-fermion behavior have been predicted and observed in moir\'e materials. The electric tunability of moir\'e materials allows an in-situ study of Kondo lattices' phase diagrams, which is not possible with their intermetallic counterparts. However, moir\'e platforms rely on twisting, which introduces twisting angle disorder and undesired buckling. Here we propose device layouts for one- and two-dimensional gate-defined superlattices in Bernal bilayer graphene where localized states couple to dispersive valley-helical modes. 16We show that, under electronic interactions, these superlattices are described by an electrically-tunable Kondo-Heisenberg model.