Modeling of Transport and Pseudo-Magnetotransport in Graphene

Graphene, a 2D material consisting of carbon atoms, despite its simple structure and composition can host intriguing phenomena. It’s tunability by e.g. electrostatic potential, strain, or twist angle between stacked layers of graphene makes it an attractive candidate for various applications.

Firstly, we will discuss transport in large-angle twisted bilayer graphene. For large twist angle, the Dirac cones of the two layers are separated in the k-space. The large momentum difference between them suppresses interlayer scattering, which makes the layers electronically decoupled. However, they are capacitively coupled because the electric charge on one layer causes an effective gating of the other layer. This effect is especially pronounced at high magnetic field, leading to distinctive Landau level pattern, as observed in experiment and in transport calculations.

Next, we consider transport in strained graphene. Application of inhomogeneous strain can lead to pseudomagnetic field (PMF), predicted to have opposite sign in the K and K′ valley. Specially designed strain have been designed to generate uniform pseudomagnetic field in graphene. We apply these strain fields to model pseudo-magnetotransport phenomena, including electron focusing and snake states. Our investigations open new possibilities for control over the valley degree of freedom.