Graphene Quantum Strain Transistors

We present an applied theoretical model for ballistic transport in uniaxially strained graphene. This model combines theoretical transport models with realistic experimental limitations originating from suspended device design, materials, and instrumentation. We find clear theoretical evidence for the possibility of high on/off ratio transistors in uniaxially strained ballistic graphene. We refer to these devices as graphene quantum strain transistors. We include realistic values for device dimensions (L = 100 nm, W = 1000 nm), contact doping (0.05 - 0.25 eV), and experimentally available strain (2.5 - 5.0 %) in a break-junction geometry. In this model, we consider first order strain effects which deform the Dirac cones, and shift the energy and momentum positions of the Dirac points. At sufficient strains, there is total internal reflection of the charge carriers at low gate voltages. As a result, we calculate on/off ratios > 10⁴ in our graphene quantum strain transistors, tunable by both strain and gate voltage. We show how experimental strain-tunable transport can be used to calibrate the applied strain, and determine crystal chirality and contact doping of the devices. Finally, we present initial experimental data which supports the predictions of our model.