Anomalous Hall effect and two-dimensional Fermi surfaces in the charge-density-wave state of kagome metal RbV<sub>3</sub>Sb<sub>5</sub>
Lingfei Wang, Wei Zhang, Zheyu Wang, Tsz Fung Poon, Wenyan Wang, Chun Wai Tsang, Jianyu Xie, Xuefeng Zhou, Yusheng Zhao, Shanmin Wang, Kwing To Lai, Swee K. Goh
Abstract
Abstract AV 3 Sb 5 (A = Cs, K, Rb) is a recently discovered superconducting system ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>T</mml:mi> <mml:mrow> <mml:mi mathvariant="normal">c</mml:mi> </mml:mrow> </mml:msub> <mml:mo>∼</mml:mo> <mml:mn>0.9</mml:mn> </mml:math> –2.5 K) in which the vanadium atoms adopt the kagome structure. Intriguingly, these systems enter a charge-density-wave (CDW) phase ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>T</mml:mi> <mml:mrow> <mml:mi mathvariant="normal">C</mml:mi> <mml:mi mathvariant="normal">D</mml:mi> <mml:mi mathvariant="normal">W</mml:mi> </mml:mrow> </mml:msub> <mml:mo>∼</mml:mo> <mml:mn>80</mml:mn> </mml:math> –100 K), and further evidence shows that the time-reversal symmetry is broken in the CDW phase. Concurrently, the anomalous Hall effect (AHE) has been observed in KV 3 Sb 5 and CsV 3 Sb 5 inside the novel CDW phase. Here, we report a comprehensive study of a high-quality RbV 3 Sb 5 single crystal with magnetotransport measurements. Our data demonstrate the emergence of the AHE in RbV 3 Sb 5 when the CDW state develops. The magnitude of the anomalous Hall resistivity in the low temperature limit is comparable to the reported values in KV 3 Sb 5 and CsV 3 Sb 5 . The magnetoresistance channel further reveals a rich spectrum of quantum oscillation frequencies, many of which have not been reported before. In particular, a large quantum oscillation frequency (2235 T), which occupies ∼56% of the Brillouin zone area, was recorded. For the quantum oscillation frequencies with sufficient signal-to-noise ratio, we further perform field angle-dependent measurements, and our data indicate two-dimensional Fermi surfaces in RbV 3 Sb 5 . Our results provide indispensable information for understanding the AHE and band structure in kagome metal AV 3 Sb 5 .