  Superconductivity in topological kagome metals has recently received great
research interests. Here, charge density wave (CDW) orders and the evolution of
superconductivity under various pressures in CsV3Sb5 single crystal with V
kagome lattice are investigated. By using high-resolution scanning tunnelling
microscopy /spectroscopy (STM/STS), two CDW orders in CsV3Sb5 are observed
which correspond to 4a*1a and 2a*2a superlattices. By applying pressure, the
superconducting transition temperature Tc is significantly enhanced and reaches
a maximum value of 8.2 K at around 1 GPa. Accordingly, CDW state is gradually
declined as increasing the pressure, which indicates the competing interplay
between CDW and superconducting state in this material. The broad
superconducting transitions around 0.4 - 0.8 GPa can be related to the strong
competition relation among two CDW states and superconductivity. These results
demonstrate that CsV3Sb5 is a new platform for exploring the interplay between
superconductivity and CDW in topological kagome metals.
