Orbital selective Kondo effect in heavy fermion superconductor UTe2

Date

2022

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Abstract

Heavy fermion systems emerge from the collective Kondo effect, and their superconductivity can serve as a promising platform for realizing next-generation quantum technologies. However, it has been a great challenge to explore many-body effects in heavy fermion systems with ab-initio approaches. We computed the electronic structure of UTe2 without purposive judgements, such as intentional selection of on-site Coulomb interaction and disregarding spin-orbit coupling. We show that U-5f electrons are highly localized in the paramagnetic normal state, giving rise to the Kondo effect. It is also found that the hybridization between U-5f and U-6d predominantly in the orthorhombic ab-plane is responsible for the high-temperature Kondo effect. In contrast, the hybridization between U-5f and Te-5p along the c-axis manifests the Kondo scattering at a much lower temperature, which could be responsible for the low-temperature upturn of the c-axis resistivity. Our results show that the electron correlation in UTe2 is orbital selective, which naturally elucidates the recent experimental observations of anomalous temperature dependence of resistivity. Furthermore, we suggest that the Kondo effect is suppressed at high pressure owing to weak localization of magnetic moments, which results from enhanced U-5f electron hopping. Our discovery provides significant insight toward understanding anisotropic quantum behavior including selective re-entrant superconductivity in heavy fermion UTe2.

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Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Keywords

Heavy fermion systems, Kondo effect, Superconductivity, Ab-initio, Spin-orbit coupling, Hybridization, Orthorhombic ab-plane

Citation

Kang, B., Choi, S. & Kim, H. Orbital selective Kondo effect in heavy fermion superconductor UTe2. npj Quantum Mater. 7, 64 (2022). https://doi.org/10.1038/s41535-022-00469-z

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