How close can one approach the Dirac point in graphene experimentally?

Understand

The above question is frequently asked by theorists who are interested in graphene as a model system, especially in context of relativistic quantum physics.

• We offer an experimental answer by describing electron transport in suspended devices with carrier mobilities of several 10^6 cm^2V^-1s^-1 and with the onset of Landau quantization occurring in fields below 5 mT.
• The observed charge inhomogeneity is as low as \approx10^8 cm^-2, allowing a neutral state with a few charge carriers per entire micron-scale device.
• Above liquid helium temperatures, the electronic properties of such devices are intrinsic, being governed by thermal excitations only.