Orbital magnetism and the loop currents (LCs) that accompany it have been proposed to emerge in many systems, including cuprates, iridates, and kagome superconductors. In the case of cuprates, LCs have been put forward as the driving force behind the pseudogap, strange-metal behavior, and d_{x^2−y^2}-wave superconductivity. Here, we investigate whether fluctuating intra-unit-cell LCs can cause unconventional superconductivity. For odd-parity LCs, we find that they are repulsive in all pairing channels near the underlying quantum-critical point (QCP). For even-parity LCs, their fluctuations give rise to unconventional pairing, which is not amplified in the vicinity of the QCP, in sharp contrast to pairing mediated by spin-magnetic, nematic, or ferroelectric fluctuations. Applying our formalism to the cuprates, we conclude that fluctuating intra-unit-cell LCs are unlikely to yield d_{x^2−y^2}-wave superconductivity. If LCs are to be relevant for the cuprates, they must break translation symmetry.

https://www.science.org/doi/10.1126/sciadv.adn3662

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https://us06web.zoom.us/j/5081440931

Meeting ID: 508 144 0931

Seminar hosts: Neven Šantić i Matija Čulo