Super-geometric electron focusing on the hexagonal Fermi surface of PdCoO<sub>2 </sub>

ORAL

Abstract

The ultrapure delafossite metal PdCoO2 exhibits a strikingly long mean free path of ∼20 µm at temperatures below 20K. Owing to its peculiar Fermi surface, resembling a nearly perfect hexagon, the electron’s ballistic trajectories are mainly restricted into three directions, rendering PdCoO2 an ideal material to investigate unusual anisotropic ballistic effects. We fabricate ballistic structures for transverse electron focusing from as-grown single crystals using focused ion beam machining, and demonstrate magnetic focusing up to 35 µm. Compared to typically studied materials with circular Fermi surfaces, the transverse focusing amplitude is strongly enhanced due to the large parallel sections of the hexagonal Fermi surface. We demonstrate this focusing enhancement experimentally, and corroborate it by transport simulations.

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Presenters

  • Maja Bachmann

    • Max Planck Institute for Chemical Physics of Solids
    • Physics, Stanford University

Authors

  • Maja Bachmann

    • Max Planck Institute for Chemical Physics of Solids
    • Physics, Stanford University

  • Aaron Sharpe

    • Physics, Stanford University
    • Stanford Univ
    • Stanford

  • Arthur W Barnard

    • Stanford Univ
    • Physics, Stanford University

  • Carsten Putzke

    • Institute of Material Science and Engineering, Ecole Polytechnique Federale de Lausanne
    • Ecole Polytechnique Federale de Lausanne
    • École Polytechnique Fédéral de Lausanne
    • University of Bristol

  • Markus Koenig

    • Max-Planck-Institute for Chemical Physics of Solids
    • Max Planck Institut for Chemical Physics of Solids
    • Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
    • Max Planck Institute for Chemical Physics of Solids

  • Seunghyun Khim

    • Max Planck Institute for Chemical Physics of Solids
    • Max Planck Institut for Chemical Physics of Solids
    • Max Planck Institute for Chemical Physics of Solids, Dresden, Germany

  • David Goldhaber-Gordon

    • Stanford Univ
    • Physics, Stanford University
    • Stanford
    • Department of Physics, Stanford University

  • Andrew Mackenzie

    • Max Planck Institute for Chemical Physics of Solids
    • Max Planck Institut for Chemical Physics of Solids
    • Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
    • MPI CPfS, Dresden, Germany

  • Philip Moll

    • Institute of Material Science and Engineering, Ecole Polytechnique Federale de Lausanne
    • Ecole Polytechnique Federale de Lausanne
    • École Polytechnique Fédéral de Lausanne
    • Institute of Materials (IMX), EPFL
    • Ecole polytechnique federale de Lausanne