How close can one approach the Dirac point in graphene experimentally?
arXiv:1206.3848 · doi:10.1021/nl301922d
Abstract
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. This yields that the Dirac point can be approached within 1 meV, a limit currently set by the remaining charge inhomogeneity. No sign of an insulating state is observed down to 1 K, which establishes the upper limit on a possible bandgap.
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Cited by in corpus (6)
- Monte-Carlo study of the electron transport properties of monolayer graphene within the tight-binding model
- Surface polar optical phonon interaction induced many-body effects and hot-electron relaxation in graphene
- Density dependent electrical conductivity in suspended graphene: Approaching the Dirac point in transport
- Graphene single electron transistor as a spin sensor for magnetic adsorbates
- Gate tunable quantum transport in double layer graphene
- Green functions in graphene monolayer with Coulomb interactions taken into account