A tutorial on graphene quantum strain transistors

Mechanical strain in graphene can be used to directly tune its energy states, acting analogously to a magnetic field. However, despite great efforts, theoretical predictions based on strain in graphene have not been realized experimentally. In this tutorial, we aim to bridge the gap between experiment and theory for a strained graphene system, showing how simple theoretical modeling becomes more powerful with experimental insights. As a platform to explore this relationship between theory and experiment, we will be using quantum electron transport in graphene.  

We will first show that electrons in graphene, unlike in conventional materials, behave more like photons, with energy linear momentum; E=pc. This dramatically changes how electrons scatter off of potential barriers. Using a simple mesoscopic model, we will derive an expression for the resulting electron conductivity in graphene, and then make predictions for quantum devices with realistic system parameters. The knowledge gained from this theoretical modeling tells us how to engineer the best devices to experimentally measure different physical phenomena. We will conclude the tutorial by including mechanical strain in our model and exploring how this tunes the electron transmission. For high strains, we predict conductance to go to zero, forming a quantum strain transistor. In a future research seminar, we will present experimental data from a real graphene system and compare it with the model developed in this tutorial.

All Faculty, staff and students are invited
Coffee will be served in the Department of Physics
SP-367-11 at 2:30  PM
Information: 514 848-2424 ext. 3270