Chiral pair density wave as a precursor of the pseudogap in kagomé superconductors

Abstract

Motivated by scanning tunneling microscopy experiments on $A$V${}_3$Sb${}_5$ ($A$ = Cs, Rb, K) that revealed periodic real-space modulation of electronic states at low energies, I show using model calculations that a triple-{\bf Q} chiral pair density wave (CPDW) is generated in the superconducting state by a charge order of $2a\times 2a$ superlattice periodicity, intertwined with a time-reversal symmetry breaking orbital loop current. In the presence of such a charge order and orbital loop current, the superconducting critical field is enhanced beyond the Chandrasekhar-Clogston limit. The CPDW correlation survives even when the long-range superconducting phase coherence is diminished by a magnetic field or temperature, stabilizing an exotic granular superconducting state above and in the vicinity of the superconducting transition. The presented results suggest that the CPDW can be regarded as the origin of the pseudogap observed near the superconducting transition.

6 pages, 5 figures

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Cited by in corpus (5)

• Chiral kagome superconductivity modulations with residual Fermi arcs in KV3Sb5 and CsV3Sb5
• Chiral pair density waves with residual Fermi arcs in RbV3Sb5
• Optimally scrambling chiral spin-chain with effective black hole geometry
• Switchable chiral 2x2 pair density wave in pure CsV3Sb5
• Phase-sensitive evidence for pair density waves in a kagome superconductor