Quantum transport evidence of topological band structures of kagome superconductor CsV3Sb5

Abstract: We report the transport properties of kagome superconductor CsV${3}$Sb${5}$ single crystals at magnetic field up to 32 T. The Shubnikov de Haas (SdH) oscillations emerge at low temperature and four frequencies of $F_{\alpha}=$ 27 T, $F_{\beta}=$ 73 T, $F_{\epsilon}=$ 727 T, and $F_{\eta}=$ 786 T with relatively small cyclotron masses are observed. For $F_{\beta}$ and $F_{\epsilon}$, the Berry phases are close to $\pi$, providing a clear evidence of nontrivial topological band structures of CsV${3}$Sb${5}$. Furthermore, the consistence between theoretical calculations and experimental results implies that these frequencies can be assigned to the Fermi surfaces locating near the boundary of Brillouin zone and confirms that the structure with an inverse Star of David distortion could be the most stable structure at charge density wave state. These results will shed light on the nature of correlated topological physics in kagome material CsV${3}$Sb${5}$.