Evidence for Local Spots of Viscous Electron Flow in Graphene at Moderate Mobility
| Autor: | Daniel Neumaier, Sven Just, Burkay Uzlu, Zhenxing Wang, Sayanti Samaddar, Tjorven Johnsen, Markus Morgenstern, Kevin Janßen, Sha Li, Jeff Strasdas, Marcus Liebmann |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Field (physics) FOS: Physical sciences Bioengineering 02 engineering and technology 01 natural sciences law.invention Physics::Fluid Dynamics law Electric field Mesoscale and Nanoscale Physics (cond-mat.mes-hall) 0103 physical sciences General Materials Science 010306 general physics Condensed Matter - Materials Science Condensed Matter - Mesoscale and Nanoscale Physics Condensed matter physics Graphene Scattering Mechanical Engineering Materials Science (cond-mat.mtrl-sci) Scattering length Disordered Systems and Neural Networks (cond-mat.dis-nn) General Chemistry Condensed Matter - Disordered Systems and Neural Networks 021001 nanoscience & nanotechnology Condensed Matter Physics Hagen–Poiseuille equation Vortex Condensed Matter - Other Condensed Matter 0210 nano-technology Current density Other Condensed Matter (cond-mat.other) |
| Zdroj: | Nano Letters. 21:9365-9373 |
| ISSN: | 1530-6992 1530-6984 |
| Popis: | Dominating electron-electron scattering enables viscous electron flow exhibiting hydrodynamic current density patterns such as Poiseuille profiles or vortices. The viscous regime has recently been observed in graphene by non-local transport experiments and mapping of the Poiseuille profile. Here, we probe the current-induced surface potential maps of graphene field effect transistors with moderate mobility using scanning probe microscopy at room temperature. We discover micron-sized large areas appearing close to charge neutrality that show current induced electric fields opposing the externally applied field. By estimating the local scattering lengths from the gate dependence of local in-plane electric fields, we find that electron-electron scattering dominates in these areas as expected for viscous flow. Moreover, we suppress the inverted fields by artificially decreasing the electron-disorder scattering length via mild ion bombardment. These results imply that viscous electron flow is omnipresent in graphene devices, even at moderate mobility. Comment: 89 pages, 24 figures, published in Nano Letters |
| Databáze: | OpenAIRE |
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