# Transmission in graphene-topological insulator heterostructures

## TL;DR

This paper studies how the topological surface states of a 3D topological insulator are affected by depositing graphene, analyzing transmission probabilities and conductance in heterostructures with different edge orientations.

## Contribution

It introduces a low-energy model for graphene-topological insulator heterostructures and analyzes transmission and conductance features related to edge configurations.

## Key findings

- Transmission probabilities vary with edge type (zigzag vs armchair).
- Conductance shows antiresonances linked to transmission features.
- The model explains transport phenomena in graphene-topological insulator interfaces.

## Abstract

We investigate scattering of the topological surface state of a three-dimensional time-reversal invariant topological insulator when graphene is deposited on the topological-insulator surface. Specifically, we consider the (111) surface of a Bi$_2$Se$_3$-like topological insulator. We present a low-energy model for the bulk graphene-topological insulator heterostructure and we calculate the transmission probability at zigzag and armchair edges of the deposited graphene, and the conductance through graphene nanoribbon barriers and show that its features can be understood from antiresonances in the transmission probability.