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arXiv · 2308.04327

Unraveling the unusually high electrical conductivity of the delafossite metal PdCoO$_2$

Xiaoping Yao·Yechen Xun·Ziye Zhu·Shu Zhao·Wenbin Li
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Abstract

The prototypical delafossite metal PdCoO$_2$ has been the subject of intense interest for hosting exotic transport properties. Using first-principles transport calculations and theoretical modeling, we reveal that the high electrical conductivity of PdCoO$_2$ at room temperature originates from the contributions of both high Fermi velocities, enabled by Pd $4d_{z^2}-5s$ hybridization, and exceptionally weak electron-phonon coupling, which leads to a coupling strength ($\lambda=0.057$) that is nearly an order of magnitude smaller than those of common metals. The abnormally weak electron-phonon coupling in PdCoO$_2$ results from a low electronic density of states at the Fermi level, as well as the large and strongly facetted Fermi surface with suppressed Umklapp electron-phonon matrix elements. We anticipate that our work will inform the design of unconventional metals with superior transport properties.

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Xiaoping Yao, Yechen Xun, Ziye Zhu, Shu Zhao, Wenbin Li. 2023-08-08. Unraveling the unusually high electrical conductivity of the delafossite metal PdCoO$_2$. https://doi.org/10.1103/physrevb.109.075110

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