Spontaneous current orders due to odd-parity order parameters have attracted increasing attention in various strongly correlated metals. we discover a spin-fluctuation-driven charge loop current (cLC) mechanism based on the functional renormalization group 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 ($d\mathrm{S}\mathrm{C}$) phases. While the microscopic origin of the cLC has a close similarity to that of the $d\mathrm{S}\mathrm{C}$, the cLC transition temperature $T_{\mathrm{cLC}}$ can be higher than the $d\mathrm{S}\mathrm{C}$ one for a 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.

• Received 16 October 2020
• Revised 26 February 2021
• Accepted 6 April 2021

DOI:https://doi.org/10.1103/PhysRevB.103.L161112