2026-06-03T23:24:48Z https://archive.materialscloud.org/oai2d

oai:materialscloud.org:1469 2022-11-04T09:42:32Z openaire_data community-mcarchive

Esswein, Tobias Spaldin, Nicola A. Esswein, Tobias Spaldin, Nicola A. 2022-11-04 Motivated by the recent experimental discovery of strongly surface-plane-dependent superconductivity at surfaces of KTaO₃ single crystals, we calculate the electron-phonon coupling strength, λ, of doped KTaO₃ along the reciprocal-space high-symmetry directions. Using the Wannier-function approach implemented in the EPW package, we calculate λ across the experimentally covered doping range and compare its mode-resolved distribution along the [001], [110] and [111] directions. We find that the electron-phonon coupling is strongest in the optical modes around the Γ point, with some distribution to higher k values in the [001] direction. The electron-phonon coupling strength as a function of doping has a dome-like shape in all three directions, and is largest in the [001] direction and weakest in the [111] direction. This is in contrast to the experimentally measured critical temperatures, which are highest for the (111) plane, pointing to a non-BCS character of the superconductivity. The strong localization of λ in the soft optical modes around Γ suggests an importance of ferroelectric soft-mode fluctuations. text/markdown application/zip text/plain https://doi.org/10.24435/materialscloud:7z-wx oai:materialscloud.org:1469 mcid:2022.136 eng Materials Cloud https://doi.org/10.48550/arXiv.2210.14113 https://archive.materialscloud.org/communities/mcarchive https://doi.org/10.24435/materialscloud:83-xf info:eu-repo/semantics/openAccess Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode electron-phonon coupling KTaO3 ab initio First-principles calculation of electron-phonon coupling in doped KTaO₃ info:eu-repo/semantics/other