Unlikelihood of a phonon mechanism for the high-temperature superconductivity in La3Ni2O7

You, Jing-Yang; Zhu, Zien; Del Ben, Mauro; Chen, Wei; Li, Zhenglu

doi:10.1038/s41524-024-01483-4

Title: Unlikelihood of a phonon mechanism for the high-temperature superconductivity in La₃Ni₂O₇

Journal Article · 05 January 2025 · npj Computational Materials

DOI: https://doi.org/10.1038/s41524-024-01483-4 · OSTI ID:2496794

You, Jing-Yang ^[1];

^[2]; Del Ben, Mauro ^[3]; Chen, Wei ^[4];

^[2]

National University of Singapore (Singapore); University of Southern California, Los Angeles, CA (United States)
University of Southern California, Los Angeles, CA (United States)
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
National University of Singapore (Singapore)

The discovery of ~80 K superconductivity in nickelate La₃Ni₂O₇ under pressure has ignited intense interest. Here, we present a comprehensive first-principles study of the electron-phonon (e-ph) coupling in La₃Ni₂O₇ and its implications on the observed superconductivity. Our results conclude that the e-ph coupling is too weak (with a coupling constant λ ≲ 0.5) to account for the high T_c, albeit interesting many-electron correlation effects exist. While Coulomb interactions (via GW self-energy and Hubbard U) enhance the e-ph coupling strength, electron doping (oxygen vacancies) introduces no major changes. Additionally, different structural phases display varying characteristics near the Fermi level, but do not alter the conclusion. The e-ph coupling landscape of La₃Ni₂O₇ is intrinsically different from that of infinite-layer nickelates. These findings suggest that a phonon-mediated mechanism is unlikely to be responsible for the observed superconductivity in La₃Ni₂O₇, pointing instead to an unconventional nature.

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Research Organization:: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

Sponsoring Organization:: National Science Foundation (NSF); Singapore National Research Foundation; USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES), Materials Sciences & Engineering Division; USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF)

Grant/Contract Number:: AC02-05CH11231; AC05-00OR22725

OSTI ID:: 2496794

Journal Information:: npj Computational Materials, Journal Name: npj Computational Materials Journal Issue: 1 Vol. 11; ISSN 2057-3960

Publisher:: Nature Publishing GroupCopyright Statement

Country of Publication:: United States

Language:: English

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Title: Unlikelihood of a phonon mechanism for the high-temperature superconductivity in La3Ni2O7

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Title: Unlikelihood of a phonon mechanism for the high-temperature superconductivity in La₃Ni₂O₇