Metallic phase of disordered graphene superlattices with long-range correlations

TL;DR

This paper demonstrates that long-range correlated disorder in graphene superlattices can induce a metallic phase by reviving particle transmission, with a phase transition influenced by disorder strength and energy.

Contribution

It reveals how long-range correlations in disorder can restore conductance in graphene superlattices, introducing a phase transition dependent on correlation exponent.

Findings

Transmission is suppressed with white noise disorder.

Long-range correlations revive transmission over a wide angle range.

A phase transition to metallic behavior occurs depending on correlation strength.

Abstract

Using the transfer matrix method, we study the conductance of the chiral particles through a monolayer graphene superlattice with long-range correlated disorder distributed on the potential of the barriers. Even though the transmission of the particles through graphene superlattice with white noise potentials is suppressed, the transmission is revived in a wide range of angles when the potential heights are long-range correlated with a power spectrum $S(k)\sim1/k^{\beta}$. As a result, the conductance increases with increasing the correlation exponent values gives rise a metallic phase. We obtain a phase transition diagram in which a critical correlation exponent depends strongly on disorder strength and slightly on the energy of the incident particles. The phase transition, on the other hand, appears in all ranges of the energy from propagating to evanescent mode regimes.