Band splitting and enhanced charge density wave modulation in Mn-implanted CsV(3)Sb(5)

Kagome metal CsV(3)Sb(5) has attracted unprecedented attention due to the charge density wave (CDW), Z(2) topological surface states and unconventional superconductivity. However, how the paramagnetic bulk CsV(3)Sb(5) interacts with magnetic doping is rarely explored. Here we report a Mn-doped CsV(3)Sb(5) single crystal successfully achieved by ion implantation, which exhibits obvious band splitting and enhanced CDW modulation via angle-resolved photoemission spectroscopy (ARPES). The band splitting is anisotropic and occurs in the entire Brillouin region. We observed a Dirac cone gap at the K point but it closed at 135 K ± 5 K, much higher than the bulk value of ∼94 K, suggesting enhanced CDW modulation. According to the facts of the transferred spectral weight to the Fermi level and weak antiferromagnetic order at low temperature, we ascribe the enhanced CDW to the polariton excitation and Kondo shielding effect. Our study not only offers a simple method to realize deep doping in bulk materials, but also provides an ideal platform to explore the coupling between exotic quantum states in CsV(3)Sb(5).