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Electron hydrodynamics - microscopic origins and effects of nanoscale geometries

ORAL

Abstract

Electrons in condensed matter can flow collectively when their momentum is conserved during microscopic scattering processes. Recently, this hydrodynamic regime has been observed in a handful of materials classes at moderately low temperatures and small lengthscales.1-2 The reason for this narrow temperature/lengthscale regime is the competition between the ballistic (low temperatures/small lengthscales) and diffusive (high temperatures/large lengthscales) regimes.

In this work, we compute temperature-resolved viscosity tensors for a broad range of materials from first principles and identify diagnostic tools for hydrodynamic behavior from microscopic scattering lifetimes. We then investigate the effect of nanoscale geometries on these viscous electron fluids, by comparing the results of the electronic Navier stokes equation with ab-initio viscosity tensors,3 to an independent calculation of the spatially-resolved Boltzmann transport equation using the same ab-initio scattering matrix.4

1 Sulpizio, J. A. et al. Nature 576, 75–79 (2019).
2 Vool, U., Hamo, A., Varnavides, G., Yaxian, W. et al arXiv:2009.04477 (2020)
3 Varnavides, G., Jermyn, A.S., Anikeeva, P. et al. Nat Commun 11, 4710 (2020)
4 Varnavides G., Jermyn A.S., Anikeeva P. et al. Phys. Rev. B 100 115402 (2019)

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Presenters

  • Georgios Varnavides

    Harvard University, Department of Materials Science and Engineering, Massachusetts Institute of Technology MIT

Authors

  • Georgios Varnavides

    Harvard University, Department of Materials Science and Engineering, Massachusetts Institute of Technology MIT

  • Adam Jermyn

    Center for Computational Astrophysics, Flatiron Institute

  • Yaxian Wang

    Ohio State Univ - Columbus, Harvard University, John A. Paulson School of Engineering and Applied Sciences, Harvard University

  • Uri Vool

    Harvard University, Department of Physics, Harvard University

  • Assaf Hamo

    Harvard University, Department of Physics, Harvard University

  • Amir Yacoby

    Department of Physics, Harvard University, Harvard University

  • Polina Anikeeva

    Department of Materials Science and Engineering, Massachusetts Institute of Technology, Department of Materials Science and Engineering, Massachusetts Institute of Technology MIT

  • Prineha Narang

    Harvard University, SEAS, Harvard University, John A. Paulson School of Engineering & Applied Science, Harvard University, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Physics, Harvard University, John A. Paulson School of Engineering and Applied Sciences, Harvard University