Directional ballistic transport in the two-dimensional metal PdCoO 2 .

Autor: Bachmann MD; Max Planck Institute for Chemical Physics of Solids, Dresden, Germany.; School of Physics and Astronomy, University of St Andrews, St Andrews, UK., Sharpe AL; Department of Applied Physics, Stanford University, Stanford, CA USA.; SLAC National Accelerator Laboratory, Menlo Park, CA USA., Baker G; Department of Physics and Astronomy & Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia Canada., Barnard AW; Department of Physics, Stanford University, Stanford, CA USA., Putzke C; Max Planck Institute for Chemical Physics of Solids, Dresden, Germany.; Institute of Materials, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland., Scaffidi T; Department of Physics, University of Toronto, Toronto, Ontario Canada., Nandi N; Max Planck Institute for Chemical Physics of Solids, Dresden, Germany., McGuinness PH; Max Planck Institute for Chemical Physics of Solids, Dresden, Germany.; School of Physics and Astronomy, University of St Andrews, St Andrews, UK., Zhakina E; Max Planck Institute for Chemical Physics of Solids, Dresden, Germany.; School of Physics and Astronomy, University of St Andrews, St Andrews, UK., Moravec M; Max Planck Institute for Chemical Physics of Solids, Dresden, Germany.; School of Physics and Astronomy, University of St Andrews, St Andrews, UK., Khim S; Max Planck Institute for Chemical Physics of Solids, Dresden, Germany., König M; Max Planck Institute for Chemical Physics of Solids, Dresden, Germany., Goldhaber-Gordon D; SLAC National Accelerator Laboratory, Menlo Park, CA USA.; Department of Physics, Stanford University, Stanford, CA USA., Bonn DA; Department of Physics and Astronomy & Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia Canada., Mackenzie AP; Max Planck Institute for Chemical Physics of Solids, Dresden, Germany.; School of Physics and Astronomy, University of St Andrews, St Andrews, UK., Moll PJW; Max Planck Institute for Chemical Physics of Solids, Dresden, Germany.; Institute of Materials, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
Jazyk: angličtina
Zdroj: Nature physics [Nat Phys] 2022; Vol. 18 (7), pp. 819-824. Date of Electronic Publication: 2022 May 09.
DOI: 10.1038/s41567-022-01570-7
Abstrakt: In an idealized infinite crystal, the material properties are constrained by the symmetries of the unit cell. The point-group symmetry is broken by the sample shape of any finite crystal, but this is commonly unobservable in macroscopic metals. To sense the shape-induced symmetry lowering in such metals, long-lived bulk states originating from an anisotropic Fermi surface are needed. Here we show how a strongly facetted Fermi surface and the long quasiparticle mean free path present in microstructures of PdCoO 2 yield an in-plane resistivity anisotropy that is forbidden by symmetry on an infinite hexagonal lattice. We fabricate bar-shaped transport devices narrower than the mean free path from single crystals using focused ion beam milling, such that the ballistic charge carriers at low temperatures frequently collide with both of the side walls that define the channel. Two symmetry-forbidden transport signatures appear: the in-plane resistivity anisotropy exceeds a factor of 2, and a transverse voltage appears in zero magnetic field. Using ballistic Monte Carlo simulations and a numerical solution of the Boltzmann equation, we identify the orientation of the narrow channel as the source of symmetry breaking.
Competing Interests: Competing interestsThe authors declare no competing interests.
(© The Author(s) 2022.)
Databáze: MEDLINE
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