Projects per year
Abstract
In an idealized infinite crystal, the material properties are constrained by the symmetries of the unit cell. The pointgroup symmetry is broken by the sample shape of any finite crystal, but this is commonly unobservable in macroscopic metals. To sense the shapeinduced symmetry lowering in such metals, longlived 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 inplane resistivity anisotropy that is forbidden by symmetry on an infinite hexagonal lattice. We fabricate barshaped 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 symmetryforbidden transport signatures appear: the inplane 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.
Original language  English 

Pages (fromto)  819824 
Number of pages  7 
Journal  Nature Physics 
Volume  18 
DOIs  
Publication status  Published  9 May 2022 
Fingerprint
Dive into the research topics of 'Directional ballistic transport in the twodimensional metal PdCoO_{2}'. Together they form a unique fingerprint.Projects
 1 Finished

CM DTC 2014  2022: EPSRC centre for doctoral training in condensed matter physics: Renewal of the CMDTC
1/08/14 → 31/01/24
Project: Standard
Datasets

Directional ballistic transport in the twodimensional metal PdCoO2
Bachmann, M. (Contributor), Zenodo, 2022
Dataset