Chiral charge density wave induced by mirror symmetry breaking in kagome metal

Abstract

Abstract Kagome lattice provides a distinctive platform to investigate various correlated electron orders. Recently, an unconventional charge density wave (CDW) with novel chirality is observed in the kagome metal AV3Sb5 (A = K, Rb, Cs), and the origin of which is still unclear. Here, using a tight-binding model and the mean-field method, we calculate the electron order in the quasi-two-dimensional kagome lattice with 1/3 electron filling, and show that the chiral CDW emerges under a set of parameters with C 6 rotational symmetry but without mirror symmetry. Physically, the reason why we choose this set of parameters is based on the possible tangential distortion of the kagome lattice. Our results provide a fresh insight to understand the microscopic origin of the unconventional CDW in AV3Sb5.