Quantum Transport Evidence of Topological Band Structures of Kagome Superconductor <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>CsV</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>Sb</mml:mi></mml:mrow><mml:mrow><mml:mn>5</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:mrow></mml:math>
Yang Fu, Ningning Zhao, Zheng Chen, Qiangwei Yin, Zhijun Tu, Chunsheng Gong, Chuanying Xi, Xiangde Zhu, Yuping Sun, Kai Liu, Hechang Lei
Abstract
We report the transport properties of kagome superconductor ${\mathrm{CsV}}_{3}{\mathrm{Sb}}_{5}$ single crystals at magnetic field up to 32 T. The Shubnikov--de Haas oscillations emerge at low temperature and four frequencies of ${F}_{\ensuremath{\alpha}}=27\text{ }\text{ }\mathrm{T}$, ${F}_{\ensuremath{\beta}}=73\text{ }\text{ }\mathrm{T}$, ${F}_{\ensuremath{\epsilon}}=727\text{ }\text{ }\mathrm{T}$, and ${F}_{\ensuremath{\eta}}=786\text{ }\text{ }\mathrm{T}$ with relatively small cyclotron masses are observed. For ${F}_{\ensuremath{\beta}}$ and ${F}_{\ensuremath{\epsilon}}$, the Berry phases are close to $\ensuremath{\pi}$, providing clear evidence of nontrivial topological band structures of ${\mathrm{CsV}}_{3}{\mathrm{Sb}}_{5}$. 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 ${\mathrm{CsV}}_{3}{\mathrm{Sb}}_{5}$.