Electronic band gaps and transport properties in aperiodic bilayer graphene superlattices of Thue-Morse sequence

TL;DR

This paper explores how the electronic band structure and transport properties in Thue-Morse sequence bilayer graphene superlattices can be tuned by interlayer coupling, revealing new Dirac points and diffusive conductance behavior.

Contribution

It demonstrates the sensitivity of band gaps to interlayer coupling and the emergence of extra Dirac points, offering a new method to control transport in graphene-based structures.

Findings

Zero-$ar{k}$ gap center shifts linearly with interlayer coupling $t'$.

Extra Dirac points can emerge at non-zero $k_{y}$, affecting conductance.

Conductance obeys a diffusive law with Fano factor approaching 1/3 as sequence order increases.

Abstract

We investigate electronic band structure and transport properties in bilayer graphene superlattices of Thue-Morse sequence. It is interesting to find that the zero-$\bar{k}$ gap center is sensitive to interlayer coupling $t'$, and the centers of all gaps shift versus $t'$ at a linear way. Extra Dirac points may emerge at $k_{y}\ne$0, and when the extra Dirac points are generated in pairs, the electronic conductance obeys a diffusive law, and the Fano factor tends to be 1/3 as the order of Thue-Morse sequence increases. Our results provide a flexible and effective way to control the transport properties in graphene.