Noise properties of graphene films

We present results for the noise characteristics of graphene flakes on SiO$_{2}$ as a function of gate bias. Our results are in accord with a new tunnel/trap model~based on the interaction of graphene carriers with the underlying substrate, which incorporates trap position, energy, and barrier height for tunneling into a given trap, along with the band-structure of the graphene. We will also discuss recent work on the properties of MBE-grown GaAs on graphene, in the context of noise in spin transport.