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Geometric Control of Universal Hydrodynamic Flow in a Two-Dimensional Electron Fluid
Aydın Cem Keser, Daisy Q. Wang , Oleh Klochan, Derek Y. H. Ho, Olga A. Tkachenko, Vitaly A. Tkachenko, Dimitrie Culcer, Shaffique Adam , Ian Farrer , David Ritchie , Oleg P. Sushkov, Alexander R. Hamilton
Physical Review X, Volume: 11, Issue: 3
Swansea University Author: David Ritchie
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DOI (Published version): 10.1103/physrevx.11.031030
Fluid dynamics is one of the cornerstones of modern physics and has recently found applications in the transport of electrons in solids. In most solids, electron transport is dominated by extrinsic factors, such as sample geometry and scattering from impurities. However, in the hydrodynamic regime,...
|Published in:||Physical Review X|
American Physical Society (APS)
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Fluid dynamics is one of the cornerstones of modern physics and has recently found applications in the transport of electrons in solids. In most solids, electron transport is dominated by extrinsic factors, such as sample geometry and scattering from impurities. However, in the hydrodynamic regime, Coulomb interactions transform the electron motion from independent particles to the collective motion of a viscous “electron fluid.” The fluid viscosity is an intrinsic property of the electron system, determined solely by the electron-electron interactions. Resolving the universal intrinsic viscosity is challenging, as it affects the resistance only through interactions with the sample boundaries, whose roughness not only is unknown but also varies from device to device. Here, we eliminate all unknown parameters by fabricating samples with smooth sidewalls to achieve the perfect slip boundary condition, which has been elusive in both molecular fluids and electronic systems. We engineer the device geometry to create viscous dissipation and reveal the true intrinsic hydrodynamic properties of a 2D system. We observe a clear transition from ballistic to hydrodynamic electron motion, driven by both temperature and magnetic field. We directly measure the viscosity and electron-electron scattering lifetime (the Fermi quasiparticle lifetime) over a wide temperature range without fitting parameters and show they have a strong dependence on electron density that cannot be explained by conventional theories based on the random phase approximation.
Faculty of Science and Engineering
This work was supported by the Australian Research Council Centre of Excellence in Future LowEnergy Electronics Technologies (CE170100039). D. A. R. acknowledges support from the Engineering and Physical Sciences Research Council, United Kingdom (EP/K004077/1).