Electronic transmission through AB-BA domain boundary in bilayer graphene

TL;DR

This study investigates how electron transmission varies across AB-BA domain boundaries in bilayer graphene, revealing dependence on boundary structure, orientation, and energy, with implications for electronic control and valley polarization.

Contribution

It provides a detailed analysis of electron transmission through various boundary structures in bilayer graphene using an effective continuum model, highlighting controllable and valley-polarized transport.

Findings

Transmission depends on boundary orientation and atomic configuration.

Low-energy boundaries can be insulating or highly transparent.

Valley polarization can be achieved through boundary orientation.

Abstract

We study the electron transmission through the domain boundary on bilayer graphene separating AB and BA stacking regions. Using the effective continuum model, we calculate the electron transmission probability as a function of the electron energy and the incident angle, for several specific boundary structures. The transmission strongly depends on the crystallographic direction of the boundary and also on the atomic configuration inside. At the low energy, the boundary is either insulating or highly transparent depending on the structure. In insulating cases, the transmission sharply rises when the Fermi energy is increased to a certain level, suggesting that the electric current through the boundary can be controlled by the field effect. The boundary parallel to the zigzag direction generally have different transmission properties between the two different valleys, and this enables to generate the valley polarized current in a certain configuration. We show that those characteristic features can be qualitatively explained by the transverse momentum conservation in the position-dependent band structure in the intermediate region.