Anomalous insulator metal transition in boron nitride-graphene hybrid atomic layers

TL;DR

This paper reports an anomalous insulator-metal transition in hybrid graphene-boron nitride atomic layers, driven by doping and magnetic fields, revealing unique 2D electronic behavior distinct from other systems.

Contribution

It introduces a new 2D disordered system exhibiting a tunable insulator-metal transition due to coexistence of percolation and hopping conduction mechanisms.

Findings

Transition modulated by doping and magnetic field.

Distinct transition characteristics compared to other 2D systems.

Supported by ab-initio calculations.

Abstract

The study of two-dimensional (2D) electronic systems is of great fundamental significance in physics. Atomic layers containing hybridized domains of graphene and hexagonal boron nitride (h-BNC) constitute a new kind of disordered 2D electronic system. Magneto-electric transport measurements performed at low temperature in vapor phase synthesized h-BNC atomic layers show a clear and anomalous transition from an insulating to a metallic behavior upon cooling. The observed insulator to metal transition can be modulated by electron and hole doping and by the application of an external magnetic field. These results supported by ab-initio calculations suggest that this transition in h-BNC has distinctly different characteristics when compared to other 2D electron systems and is the result of the coexistence between two distinct mechanisms, namely, percolation through metallic graphene networks and hopping conduction between edge states on randomly distributed insulating h-BN domains.