Bulletin of the American Physical Society
APS March Meeting 2021
Monday–Friday, March 15–19, 2021; Virtual; Time Zone: Central Daylight Time, USA
Session Y58: Hydrodynamic Electron Flow
11:30 AM–2:30 PM,
Friday, March 19, 2021
Sponsoring Unit: DCMP
Chair: James Hone, Columbia Univ
Abstract: Y58.00005 : Geometric control of universal hydrodynamic flow in a two dimensional electron fluid
1:54 PM–2:30 PM
Here we introduce a new approach to studying hydrodynamic flow. We demonstrate this technique with 2D electrons in a GaAs/AlGaAs heterostructure device with smooth sidewalls to eliminate all unknown sample boundary conditions and other extrinsic factors, and then controllably re-introduce viscous dissipation by deliberately engineering the shape of the sample boundaries. This allows the viscosity and electron-electron scattering length to be measured without any fitting parameters. We observe a clear transition from ballistic to hydrodynamic electron motion driven by both temperature and also by magnetic field. We observe an unexpected deviation of the e-e scattering length from existing theoretical models based on the Random Phase and Hubbard Approximations.
This boundary engineering technique provides a new quantitative approach to measure the electron quasiparticle lifetime, a fundamental concept in Fermi liquid theory, over a much wider range of $T$ and $B$ than has previously been possible.
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