Transport in Graphene: Ballistic or Diffusive?

Abstract

We investigate the transport of electrons in disordered and pristine graphene devices. Fano shot noise, a standard metric to assess the mechanism for electronic transport in mesoscopic devices, has been shown to produce almost the same magnitude ($\approx 1/3$) in ballistic and diffusive graphene devices and is therefore of limited applicability. We consider a two-terminal geometry where the graphene flake is contacted by narrow metallic leads. We propose that the dependence of the conductance on the position of one of the leads, a conductance profile, can give us insight into the charge flow, which can in turn be used to analyze the transport mechanism. Moreover, we simulate scanning probe microscopy (SPM) measurements for the same devices, which can visualize the flow of charge inside the device, thus complementing the transport calculations. From our simulations, we find that both the conductance profile and SPM measurements are excellent tools to assess the transport mechanism differentiating ballistic and diffusive graphene systems.

11 pages, 7 figures. Renamed by editorial staff as "Ballistic versus diffusive transport in graphene"

References in corpus (22)

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• The electronic properties of graphene
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• Boron nitride substrates for high-quality graphene electronics
• The structure of suspended graphene sheets
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• Phase Coherent Transport of Charges in Graphene Quantum Billiard
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• Shot Noise in Ballistic Graphene
• Shot Noise in Graphene
• Conductivity and Fano factor in disordered graphene
• Effective contact model for transport through weakly-doped graphene
• Electron density distribution and screening in rippled graphene sheets
• Electronic transport in normal-conductor/graphene/normal-conductor junctions and conditions for insulating behavior at a finite charge-carrier density
• Transport regimes in surface disordered graphene sheets
• Charge transport through graphene junctions with wetting metal leads
• Signature of chirality in scanning-probe imaging of charge flow in graphene

Cited by in corpus (8)

• Size quantization of Dirac fermions in graphene constrictions
• Theoretical analysis of a dual-probe scanning tunneling microscope setup on graphene
• Thermoelectric and thermospin transport in a ballistic junction of graphene
• Effect of out-of-plane acoustic phonons on the thermal transport properties of graphene
• Ballistic transport properties in pristine-doped-pristine graphene junctions
• Conductance of graphene flakes contacted at their corners
• Intermediate diffusive-ballistic electron conduction around mesoscopic defects in graphene
• Effect of Uncorrelated On-site Scalar Potential and Mass Disorder on Transport of Two-Dimensional Dirac Fermions