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arXiv · 2103.08925

Unconventional Pairing from Local Orbital Fluctuations in Strongly Correlated A$_3$C$_{60}$

Changming Yue·Shintaro Hoshino·Akihisa Koga·Philipp Werner
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Abstract

The pairing mechanism in A$_3$C$_{60}$ is investigated by studying the properties of a three-orbital Hubbard model with antiferromagnetic Hund coupling in the normal and superconducting phase. Local orbital fluctuations are shown to be substantially enhanced in the superconducting state, with a fluctuation energy scale that matches the low-energy peak in the spectral weight of the order parameter. Our results demonstrate that local orbital fluctuations provide the pairing glue in strongly correlated fulleride superconductors and support the spin/orbital freezing theory of unconventional superconductivity. They are also consistent with the experimentally observed universal relation between the gap energy and local susceptibility in a broad range of unconventional superconductors.

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Changming Yue, Shintaro Hoshino, Akihisa Koga, Philipp Werner. 2021-03-16. Unconventional Pairing from Local Orbital Fluctuations in Strongly Correlated A$_3$C$_{60}$. https://doi.org/10.1103/physrevb.104.075107

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