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Imaging phonon-mediated hydrodynamic flow in WTe2 with cryogenic quantum magnetometry

ORAL

Abstract

Hydrodynamic electron flow is a unique signature of strong electron interactions in a material. This effect has been observed in 2D materials, but observations in bulk materials are intriguing as high-carrier density should screen the interactions. In this work, we study hydrodynamic flow in the semimetal WTe2 to gain insight into the microscopic origin of its electron interactions.

We image the spatial profile of the electric current by using a nitrogen-vacancy scanning tip. Using coherent quantum sensing, we obtain magnetic field resolution of ~10nT and spatial resolution of ~100nm. The current pattern we observe differs substantially from the flat profile of a normal metal, and indicates correlated flow through the semimetal. The pattern also shows non-monotonic temperature dependence, with hydrodynamic effects peaking at ~20 K.

We compare our results to a model which combines ab initio electron scattering rates and the electronic Boltzmann transport equation.
The model shows quantitative agreement with our measurement, allowing us to extract the strength of electron-electron interactions in our material. Furthermore, we conclude that electron interactions are phonon-mediated. This result opens a path for hydrodynamic flow and strong interactions in a variety of new materials.

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Presenters

  • Uri Vool

    Harvard University, Department of Physics, Harvard University

Authors

  • Uri Vool

    Harvard University, Department of Physics, Harvard University

  • Assaf Hamo

    Harvard University, Department of Physics, Harvard University

  • Georgios Varnavides

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

  • Yaxian Wang

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

  • Tony Zhou

    Harvard University, Massachusetts Institute of Technology MIT

  • Nitesh Kumar

    Solid State Chemistry, Max Planck Institute for Chemical Physics of Solids, Max Planck Institute for Chemical Physics of Solids

  • Yuliya Dovzhenko

    Harvard University

  • Ziwei Qiu

    Harvard University

  • Christina Garcia

    Harvard University

  • Andrew Pierce

    Department of Physics, Harvard University, Harvard University

  • Johannes Gooth

    Max Planck Institute for Chemical Physics of Solids

  • Polina Anikeeva

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

  • Claudia Felser

    Max Planck Institute for Chemical Physics of Solids, Max Planck Institute for the Chemical Physics of Solids, Solid State Chemistry, Max Planck Institute for Chemical Physics of Solids, Max Planck Institute, Dresden, Germany, Max Planck, Dresden, Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Max Planck Institute for Chemical Physics of Solids,

  • 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

  • Amir Yacoby

    Department of Physics, Harvard University, Harvard University