Crossing the ballistic-ohmic transition via high energy electron irradiation
Abstract
The delafossite metal PtCoO2 is among the highest-purity materials known, with low-temperature mean free path up to 5 μm in the best as-grown single crystals. It exhibits a strongly faceted, nearly hexagonal Fermi surface. This property has profound consequences for nonlocal transport within this material, such as in the classic ballistic-regime measurement of bend resistance in mesoscopic squares. Here, we report the results of experiments in which high-energy electron irradiation was used to introduce pointlike disorder into such squares, reducing the mean free path and therefore the strength of the ballistic-regime transport phenomena. We demonstrate that high-energy electron irradiation is a well-controlled technique to cross from nonlocal to local transport behavior and therefore determine the nature and extent of unconventional transport regimes. Using this technique, we confirm the origins of the directional ballistic effects observed in delafossite metals and demonstrate how the strongly faceted Fermi surface both leads to unconventional transport behavior and enhances the length scale over which such effects are important.
Citation
Zhakina , E , McGuinness , P H , König , M , Grasset , R , Bachmann , M D , Khim , S , Putzke , C , Moll , P J W , Konczykowski , M & Mackenzie , A P 2023 , ' Crossing the ballistic-ohmic transition via high energy electron irradiation ' , Physical Review B , vol. 107 , no. 9 , 094203 . https://doi.org/10.1103/PhysRevB.107.094203
Publication
Physical Review B
Status
Peer reviewed
ISSN
2469-9950Type
Journal article
Description
Funding: P.H.M. and M.D.B. received PhD studentship support from the UK Engineering and Physical Science Research Council via Grant No. EP/L015110/1. C.P. and P.J.W.M. are supported by the European Research Council under the European Union's Horizon 2020 research and innovation programme (Microstructured Topological Materials Grant No. 715730). E. Z. acknowledges support from the International Max Planck Research School for Chemistry and Physics of Quantum Materials (IMPRS-CPQM). Irradiation experiments performed on the SIRIUS platform were supported by the French National Network of Accelerators for Irradiation and Analysis of Molecules and Materials (EMIR&A) under Project No. EMIR 2019 18-7099.Collections
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