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Research output: Contribution to Journal/Magazine › Letter › peer-review
Research output: Contribution to Journal/Magazine › Letter › peer-review
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TY - JOUR
T1 - Superballistic flow of viscous electron fluid through graphene constrictions
AU - Krishna Kumar, Roshan
AU - Bandurin, D. A.
AU - Pellegrino, F. M. D.
AU - Cao, Y.
AU - Principi, A.
AU - Guo, H.
AU - Auton, G. H.
AU - Ben Shalom, Moshe
AU - Ponomarenko, Leonid Alexandrovich
AU - Falkovich, G.
AU - Watanabe, K.
AU - Taniguchi, T.
AU - Grigorieva, I. V.
AU - Levitov, L. S.
AU - Polini, M.
AU - Geim, A. K.
N1 - © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.
PY - 2017/12/1
Y1 - 2017/12/1
N2 - Electron–electron (e–e) collisions can impact transport in a variety of surprising and sometimes counterintuitive ways1,2,3,4,5,6. Despite strong interest, experiments on the subject proved challenging because of the simultaneous presence of different scattering mechanisms that suppress or obscure consequences of e–e scattering7,8,9,10,11. Only recently, sufficiently clean electron systems with transport dominated by e–e collisions have become available, showing behaviour characteristic of highly viscous fluids12,13,14. Here we study electron transport through graphene constrictions and show that their conductance below 150 K increases with increasing temperature, in stark contrast to the metallic character of doped graphene15. Notably, the measured conductance exceeds the maximum conductance possible for free electrons16,17. This anomalous behaviour is attributed to collective movement of interacting electrons, which ‘shields’ individual carriers from momentum loss at sample boundaries18,19. The measurements allow us to identify the conductance contribution arising due to electron viscosity and determine its temperature dependence. Besides fundamental interest, our work shows that viscous effects can facilitate high-mobility transport at elevated temperatures, a potentially useful behaviour for designing graphene-based devices.
AB - Electron–electron (e–e) collisions can impact transport in a variety of surprising and sometimes counterintuitive ways1,2,3,4,5,6. Despite strong interest, experiments on the subject proved challenging because of the simultaneous presence of different scattering mechanisms that suppress or obscure consequences of e–e scattering7,8,9,10,11. Only recently, sufficiently clean electron systems with transport dominated by e–e collisions have become available, showing behaviour characteristic of highly viscous fluids12,13,14. Here we study electron transport through graphene constrictions and show that their conductance below 150 K increases with increasing temperature, in stark contrast to the metallic character of doped graphene15. Notably, the measured conductance exceeds the maximum conductance possible for free electrons16,17. This anomalous behaviour is attributed to collective movement of interacting electrons, which ‘shields’ individual carriers from momentum loss at sample boundaries18,19. The measurements allow us to identify the conductance contribution arising due to electron viscosity and determine its temperature dependence. Besides fundamental interest, our work shows that viscous effects can facilitate high-mobility transport at elevated temperatures, a potentially useful behaviour for designing graphene-based devices.
U2 - 10.1038/nphys4240
DO - 10.1038/nphys4240
M3 - Letter
VL - 13
SP - 1182
EP - 1185
JO - Nature Physics
JF - Nature Physics
SN - 1745-2473
ER -