Electronic band gaps and transport properties in periodically alternating mono- and bi-layer graphene superlattices

TL;DR

This paper explores the electronic band structure and transport properties of periodically alternating mono- and bi-layer graphene superlattices, revealing tunable energy gaps and the existence of extra Dirac points influenced by structural parameters.

Contribution

It introduces the concept of a zero-averaged wave vector gap in MBLG superlattices and analytically determines conditions for extra Dirac points, offering new insights into tunable graphene-based electronic devices.

Findings

Existence of a zero-$ar{k}$ gap insensitive to lattice constant

Control of the zero-$ar{k}$ gap via potential width ratio and interlayer coupling

Identification of conditions for extra Dirac points

Abstract

We investigate the electronic band structure and transport properties of periodically alternating mono- and bi-layer graphene superlattices (MBLG SLs). In such MBLG SLs, there exists a zero-averaged wave vector (zero-$\overline{k}$) gap that is insensitive to the lattice constant. This zero-$\overline{k}$ gap can be controlled by changing both the ratio of the potential widths and the interlayer coupling coefficient of the bilayer graphene. We also show that there exist extra Dirac points; the conditions for these extra Dirac points are presented analytically. Lastly, we demonstrate that the electronic transport properties and the energy gap of the first two bands in MBLG SLs are tunable through adjustment of the interlayer coupling and the width ratio of the periodic mono- and bi-layer graphene.