Intrinsic and extrinsic effects on Dirac fermions in graphene covered by Ga2O3

Matthew Gebert

Dirac fermions are found in 3D strong topological insulators and Graphene. Both these systems exhibit interesting properties, such as the coupling of spin or pseudospin to momentum. This can result in suppressed backscattering and very high velocities for particles. However, the fermions exist on the surface of these materials, and may be sensitive to their environment. Gallium oxide (Ga₂O₃) is a new passivation coating explored in FLEET to protect 2D materials but has not been investigated for Dirac electronic materials. Here, we investigate thin Ga₂O₃ as an interface layer to graphene, probing its extrinsic effect on the Dirac conduction.

About the presenter

Matthew Gebert is a PhD student in Prof Michael Fuhrer’s group at Monash University, investigating the interface between the 2D surface state of a 3D topological insulator (TI) with a thin, insulating ferromagnetic material. The aims of the project are to understand the effects of time-reversal symmetry breaking on the topological insulator and to investigate the effects of spin-polarised transport current in the topological insulator on the ferromagnet. Both aspects are of interest from the perspectives of both fundamental physics and prospects for electronics applications.

This work contributes to FLEET Research theme 2, exciton superfluids.