  The superconductivity of a kagome superconductor CsV3Sb5 is studied by
scanning tunneling microscopy / spectroscopy at an ultralow temperature with
high resolution. Two kinds of superconducting gaps with multiple sets of
coherent peaks and residual zero-energy density of states are observed on both
half-Cs and Sb surfaces, implying multiband superconductivity with gap nodes.
Sixfold star-shaped magnetic vortex is observed with conventional Caroli-de
Gennes-Matricon bound states inside. Magnetic impurities suppress the
superconductivity, while nonmagnetic impurities do not, suggesting the absence
of sign-change in the superconducting order parameter. Moreover, the interplay
between charge density waves and superconductivity differs on various bands,
resulting in different density of state distributions. Our study provides
critical clues for further understanding the superconductivity and its relation
to charge density waves in CsV3Sb5.
