Impact of the orbital current order on the superconducting properties of the kagome superconductors

Motivated by recent experimental evidence signaling chiral charge order in vanadium-based kagome super-conductors, we investigate theoretically the impact of chiral flux charge order on the experimental outcomes for normal and superconducting (SC) properties. It is revealed that the spectral weight on the Fermi surface (FS) is partially gapped by chiral flux charge order, with the reservation of the spectral weight on the M points and the midpoint between the two adjacent M points, resulting in the momentum-dependent energy gap being consistent with recent experimental observations. More importantly, by considering the influence of chiral flux charge order, we find that a conventional fully gapped SC pairing state evolves into a nodal gap feature for the spectral weight due to the spectral gap modulations on the FS. As a result, the U-shaped density of states (DOS) deforms to the V-shaped DOS along with the residual DOS near the Fermi energy. These results bear some resemblance to the experimental observations, and they may serve as a promising proposal to mediate the divergent or seemingly contradictory experimental outcomes regarding SC pairing symmetry.

Automated summary

Motivated by recent experimental evidence of chiral charge order in vanadium-based kagome superconductors, this theoretical investigation explores the impact of chiral flux charge order on normal and superconducting properties. The study finds that chiral flux charge order partially gaps the spectral weight on the Fermi surface, but preserves spectral weight on certain points, resulting in consistent energy gap patterns. Additionally, the investigation reveals that chiral flux charge order transforms a conventional fully gapped superconducting state into a nodal gap feature, accompanied by changes in density of states. These findings can potentially explain divergent experimental outcomes regarding superconducting pairing symmetry.