Orbital fluctuation induced unconventional charge density waves in Kagome metal, AV3Sb5.

Recently discovered Kagome metal, AV3Sb5 (A=K, Rb, Cs) offers intriguing opportunities to explore correlated phenomena emerging from van Hove singularities (vHs). Particularly, a variety of charge density wave (CDW) have been suggested as candidates of experimental observations. Here, we consider multiple vHs closely located in the electronic structures, so that the particle-hole condensations between them are significant to settle the kinds of CDW. Compared to the single vHs, the orbital fluctuation inside CDW orders diversifies the symmetry breaking patterns, such as nematic charge order. Different kinds of CDW orders can be interpolated as the microscopic parameters vary. Moreover, the influence to the instability of orbital current order is investigated in the presence of conventional CDW. It turns out that the orbital current is closely related to both the non-trivial band topology and unconventional superconducting orders. We discuss the experimental implications to identify these complex CDW orders.