The layered delafossite metal PdCrO2 is a natural heterostructure of highly conductive Pd layers Kondo coupled to localized spins in the adjacent Mott insulating CrO2 layers. At high temperatures, T, it has a T-linear resistivity which is not seen in the isostructural but nonmagnetic PdCoO2. The strength of the Kondo coupling is known, as-grown crystals are extremely high purity and the Fermi surface is both very simple and experimentally known. It is therefore an ideal material platform in which to investigate ?Planckian metal? physics. We do this by means of controlled introduction of point disorder, measurement of the thermal conductivity and Lorenz ratio, and studying the sources of its high-temperature entropy. The T-linear resistivity is seen to be due mainly to elastic scattering and to arise from a sum of several scattering mechanisms. Remarkably, this sum leads to a scattering rate within 10% of the Planckian value of kBT/?.
%0 Journal Article
%1 zhakina2023investigation
%A Zhakina, Elina
%A Daou, Ramzy
%A Maignan, Antoine
%A McGuinness, Philippa H.
%A König, Markus
%A Rosner, Helge
%A Kim, Seo-Jin
%A Khim, Seunghyun
%A Grasset, Romain
%A Konczykowski, Marcin
%A Tulipman, Evyatar
%A Mendez-Valderrama, Juan Felipe
%A Chowdhury, Debanjan
%A Berg, Erez
%A Mackenzie, Andrew P.
%B Proceedings of the National Academy of Sciences
%D 2023
%I Proceedings of the National Academy of Sciences
%J Proc. Natl. Acad. Sci. U.S.A.
%K a
%N 36
%P e2307334120
%R 10.1073/pnas.2307334120
%T Investigation of Planckian behavior in a high-conductivity oxide: PdCrO$_2$
%U https://doi.org/10.1073/pnas.2307334120
%V 120
%X The layered delafossite metal PdCrO2 is a natural heterostructure of highly conductive Pd layers Kondo coupled to localized spins in the adjacent Mott insulating CrO2 layers. At high temperatures, T, it has a T-linear resistivity which is not seen in the isostructural but nonmagnetic PdCoO2. The strength of the Kondo coupling is known, as-grown crystals are extremely high purity and the Fermi surface is both very simple and experimentally known. It is therefore an ideal material platform in which to investigate ?Planckian metal? physics. We do this by means of controlled introduction of point disorder, measurement of the thermal conductivity and Lorenz ratio, and studying the sources of its high-temperature entropy. The T-linear resistivity is seen to be due mainly to elastic scattering and to arise from a sum of several scattering mechanisms. Remarkably, this sum leads to a scattering rate within 10% of the Planckian value of kBT/?.
@article{zhakina2023investigation,
abstract = {The layered delafossite metal PdCrO2 is a natural heterostructure of highly conductive Pd layers Kondo coupled to localized spins in the adjacent Mott insulating CrO2 layers. At high temperatures, T, it has a T-linear resistivity which is not seen in the isostructural but nonmagnetic PdCoO2. The strength of the Kondo coupling is known, as-grown crystals are extremely high purity and the Fermi surface is both very simple and experimentally known. It is therefore an ideal material platform in which to investigate ?Planckian metal? physics. We do this by means of controlled introduction of point disorder, measurement of the thermal conductivity and Lorenz ratio, and studying the sources of its high-temperature entropy. The T-linear resistivity is seen to be due mainly to elastic scattering and to arise from a sum of several scattering mechanisms. Remarkably, this sum leads to a scattering rate within 10% of the Planckian value of kBT/?.},
added-at = {2024-02-21T12:35:36.000+0100},
author = {Zhakina, Elina and Daou, Ramzy and Maignan, Antoine and McGuinness, Philippa H. and König, Markus and Rosner, Helge and Kim, Seo-Jin and Khim, Seunghyun and Grasset, Romain and Konczykowski, Marcin and Tulipman, Evyatar and Mendez-Valderrama, Juan Felipe and Chowdhury, Debanjan and Berg, Erez and Mackenzie, Andrew P.},
biburl = {https://www.bibsonomy.org/bibtex/2726c241c545cc9ff4374947f92f05881/ctqmat},
booktitle = {Proceedings of the National Academy of Sciences},
comment = {doi: 10.1073/pnas.2307334120},
day = 23,
doi = {10.1073/pnas.2307334120},
interhash = {a15b21493bd5468ca5f5b0b5cb751b61},
intrahash = {726c241c545cc9ff4374947f92f05881},
journal = {Proc. Natl. Acad. Sci. U.S.A.},
keywords = {a},
month = {06},
number = 36,
pages = {e2307334120},
publisher = {Proceedings of the National Academy of Sciences},
timestamp = {2024-02-21T12:35:36.000+0100},
title = {Investigation of Planckian behavior in a high-conductivity oxide: PdCrO$_{\mathbf{2}}$},
url = {https://doi.org/10.1073/pnas.2307334120},
volume = 120,
year = 2023
}