Abstract
Research on the anomalous Hall effect (AHE) has been lasting for a century to make clear the underlying physical mechanism. Generally, the AHE appears in magnetic materials, in which the extrinsic process related to scattering effects and intrinsic contribution connected with Berry curvature are crucial. Recently, AHE has been counterintuitively observed in nonmagnetic topological materials and attributed to the existence of Weyl points. However, the Weyl point scenario would lead to unsaturated AHE even in large magnetic fields and contradicts the saturation of AHE in several tesla (T) in experiments. In this work, we investigate the Hall effect of ZrTe5 and HfTe5 thin flakes in static ultrahigh magnetic fields up to 33 T. We find the AHE saturates to 55(70)ω-1cm-1 for ZrTe5 (HfTe5) thin flakes above ∼10T. Combining detailed magnetotransport experiments and Berry curvature calculations, we clarify that the splitting of massive Dirac bands without Weyl points can be responsible for AHE in nonmagnetic topological materials ZrTe5 and HfTe5 thin flakes. This model can identify our thin flake samples to be weak topological insulators and serve as a tool to probe the band structure topology in topological materials.
| Original language | English |
|---|---|
| Article number | L201110 |
| Journal | Physical Review B |
| Volume | 103 |
| Issue number | 20 |
| DOIs | |
| State | Published - May 14 2021 |
Funding
We thank X. Wu and W. Zhang for the help in related experiments. B.Y. acknowledges helpful discussions with Prof. J.-H. Chu. This work was financially supported by the National Key Research and Development Program of China (Grants No. 2018YFA0305604 and No. 2017YFA0303302), the National Natural Science Foundation of China (Grants No. 11888101, No. 11774008, and No. 12004441), Beijing Natural Science Foundation (Grant No. Z180010), and the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB28000000). J.Y. and D.M. were supported by the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. H.W. acknowledges the support of the Hundreds of Talents program of Sun Yat-Sen University and the Fundamental Research Funds for the Central Universities (Grant No. 20lgpy165). B.Y. acknowledges the financial support by the Willner Family Leadership Institute for the Weizmann Institute of Science, the Benoziyo Endowment Fund for the Advancement of Science, Ruth and Herman Albert Scholars Program for New Scientists, the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (ERC Consolidator Grant No. 815869, “NonlinearTopo”). C.X. was supported by the Users with Excellence Project of Hefei Science Center CAS (Grant No. 2018HSC-UE015).