Anomalous Hall effect and two-dimensional Fermi surfaces in the charge-density-wave state of kagome metal RbV₃Sb₅

Kagome metals AV₃Sb₅ (A = K, Rb, and Cs) are recently discovered platforms featuring an unusual charge-density-wave (CDW) order (T_CDW~80-100K) and superconductivity (T_c~ 0.9-2.5 K). Recently, some evidences show that the time-reversal symmetry is broken in the CDW phase and the anomalous Hall effect (AHE) has been observed in KV₃Sb₅ and CsV₃Sb₅ inside the novel CDW phase. In this talk, I will report a comprehensive study of a high-quality RbV₃Sb₅ single crystal with magnetotransport measurements, which demonstrate the emergence of the AHE in RbV₃Sb₅ when the CDW state develops. The magnitude of the anomalous Hall resistivity in the low temperature limit is comparable to the reported values in KV₃Sb₅ and CsV₃Sb₅. The magnetoresistance channel further reveals a rich spectrum of quantum oscillation frequencies. In particular, a large quantum oscillation frequency (2235 T), which occupies ~ 56% of the Brillouin zone area was revealed, further angle-dependent measurement unequivocally indicates the presence of two-dimensional Fermi surfaces in RbV₃Sb₅. Our results provide indispensable information for understanding the AHE and band structure in kagome metal AV₃Sb₅.