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arXiv · 2010.16109

Emergence of Charge Loop Current in Geometrically Frustrated Hubbard Model: Functional Renormalization Group Study

Rina Tazai·Youichi Yamakawa·Hiroshi Kontani
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Abstract

Spontaneous current orders due to odd-parity order parameters attract increasing attention in various strongly correlated metals. Here, we discover a novel spin-fluctuation-driven charge loop current (cLC) mechanism based on the functional renormalization group (fRG) theory. The present mechanism leads to the ferro-cLC order in a simple frustrated chain Hubbard model. The cLC appears between the antiferromagnetic and $d$-wave superconducting ($d$SC) phases. While the microscopic origin of the cLC has a close similarity to that of the $d$SC, the cLC transition temperature $T_{\rm cLC}$ can be higher than the $d$SC one for wide parameter range. Furthermore, we reveal that the ferro cLC order is driven by the strong enhancement of the forward scatterings $g_2$ and $g_4$ owing to the two dimensionality based on the $g$-ology language. The present study indicates that the cLC can emerge in metals near the magnetic criticality with geometrical frustration

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Rina Tazai, Youichi Yamakawa, Hiroshi Kontani. 2020-10-30. Emergence of Charge Loop Current in Geometrically Frustrated Hubbard Model: Functional Renormalization Group Study. https://doi.org/10.1103/physrevb.103.l161112

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