The quasi-2 dimensional Kagome materials AV₃Sb₅ (A=K,Rb,Cs) was found to be the first example of Kagome superconductor [1-3], which provides us a new platform to investigate the interplay between correlation, topology and geometric frustration. In this talk, I will give a brief review of the recent progress in Kagome materials AV₃Sb₅, especially the time-reversal symmetry breaking charge density wave order found by magnetic field dependent STM and zero-field muon spin spectroscopy. Since there is no long-range magnetic order in AV₃Sb₅, we argue that the topological charge density wave phase is a chiral flux phase [6]. By symmetry analysis and energy comparison, the explicit form of the chiral flux phase was constructed. To further confirm this, we search and classify all possible flux phases in Kagome lattice within 2*2 unit cell [7]. The consequence of this chiral flux phase and its influence on superconductivity will be covered [8].

[1] B. R. Ortiz et al., Phys. Rev. Mater. 3, 094407 (2019).

[2] B. R. Ortiz et al., Phys. Rev. Lett. 125, 247002 (2020).

[3] B. R. Ortiz et al., Phys. Rev. Materials 5, 034801 (2021).

[4] Y.-X. Jiang et al., arXiv:2012.15709.

[5] Li Yu et al., arXiv:2107.10714.

[6] Xilin Feng, Kun Jiang, Ziqiang Wang, Jiangping Hu, Sci. Bull. 66, 1384 (2021).

[7] Xilin Feng, Yi Zhang, Kun Jiang, Jiangping Hu, arXiv:2106.04395.

[8] Yuhao Gu, Yi Zhang, Xilin Feng, Kun Jiang, Jiangping Hu, arXiv:2108.04703.