Hydrodynamic transport in graphene
Giorno 13 giugno 2018 alle ore 11:00, presso l'Aula F del DFA, F. M. D. Pellegrino terrà un seminario dal titolo Hydrodynamic transport in graphene. Tutti gli interessati sono invitati a partecipare.
Electron-electron (e-e) collisions can impact transport in a variety of surprising and sometimes counterintuitive ways. 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 scattering. Only recently, sufficiently clean electron systems with transport dominated by e-e collisions have become available, showing behavior characteristic of highly viscous fluids [1, 2, 3]. Examples of these new and counterintuitive measurable phenomena are the negative nonlocal resistance, the occurrence of current whirlpools, and the superballistic transport through a constriction. Furthermore, it is well known that materials subjected to a magnetic field exhibit the Hall effect, a phenomenon studied and understood in fine detail. Here, we report a qualitative breach of this classical behavior in electron systems with high viscosity. The viscous fluid in graphene is found to respond to non-quantizing magnetic fields by producing an electric field opposite to that generated by the classical Hall effect [4, 5].
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