Competing charge density waves in the kagome lattice

The exotic charge density wave order with time reversal symmetry breaking in kagome superconductors has attracted tremendous attention. However, its origin still remains elusive and its microscopic model realization has proven challenging. In this work, we investigate the competing electronic order in the kagome model with nearest-neighbor (NN) and next NN Coulomb repulsion at the van Hove filling. The sublattice texture on the Fermi surface is found to play a crucial role in determining the electronic instabilities. For weak interactions, we find the NN interaction favors a 2x2 charge bond order, while the next NN interaction promotes a 2x2 imaginary bond order, i.e. loop current order. When interactions are strong, a CDW order emerges, characterized by rotational symmetry breaking. Upon slight doping, superconductivity arises from these charge fluctuations, revealing three different pairings. Our work offers a microscopic realization of loop current order in the kagome lattice, and we also discuss potential implications for the vanadium-based kagome superconductors AV₃Sb₅.