Regensburg 2019 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 65: Two-dimensional Materials IV (joint session HL/CPP)
CPP 65.9: Vortrag
Freitag, 5. April 2019, 11:45–12:00, H36
Magnetic hallmarks of viscous electron flow in graphene — •Karina A. Guerrero-Becerra1, Francesco M. D. Pellegrino2,3, and Marco Polini1,4 — 1Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy — 2Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia, 64, I-95123 Catania, Italy — 3INFN, Sez. Catania, I-95123 Catania, Italy — 4School of Physics & Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
Electrical transport, thermal transport, and scanning gate spectroscopy measurements have been used to identify signatures of viscous electron flow in graphene, PdCoO2, and GaAs. In this regime of transport, viscosity determines electron whirlpools in the steady-state current pattern. So far, a direct experimental observation of electron whirlpools and associated backflow is still lacking. We predict that the profile of the magnetic field generated by hydrodynamic electron flow in confined geometries displays unambiguous features linked to whirlpools and backflow near current injectors. We also show that the same profiles shed light on the nature of the boundary conditions describing friction exerted on the electron fluid by the edges of the sample. Our predictions are within reach of vector magnetometry based on nitrogen-vacancy centers in diamond, a technique that access the details of 2D spatial flow patterns in graphene [1] and combines the benefits of high spatial resolution, competitive magnetic field resolution, and operability over a wide range of temperatures.
[1] J.-P. Tetienne et. al., Sci. Adv. 3, e1602429 (2017).