Abstract
The intrinsic antiferromagnetic topological insulator MnBi2Te4 undergoes a metamagnetic transition in a c-axis magnetic field. It has been predicted that ferromagnetic MnBi2Te4 is an ideal Weyl semimetal with a single pair of Weyl nodes. Here we report measurements of quantum oscillations detected in the field-induced ferromagnetic phase of MnBi2-xSbxTe4, where Sb substitution tunes the majority carriers from electrons to holes. Single-frequency Shubnikov-de Haas oscillations were observed in a wide range of Sb concentrations (0.54≤x≤1.21). The evolution of the oscillation frequency and the effective mass shows reasonable agreement with the Weyl semimetal band structure of ferromagnetic MnBi2Te4 predicted by density functional calculations. Intriguingly, the quantum oscillation frequency shows a strong temperature dependence, indicating that the electronic structure depends sensitively on magnetism.
| Original language | English |
|---|---|
| Article number | 205111 |
| Journal | Physical Review B |
| Volume | 103 |
| Issue number | 20 |
| DOIs | |
| State | Published - May 7 2021 |
Funding
We thank Wonhee Ko, Chao-Xing Liu, Zhongkai Liu, Lexian Yang, and Binghai Yan for helpful discussions. We thank David Cobden for a careful reading of the manuscript and valuable suggestions. This work is primarily supported as part of Programmable Quantum Materials, an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under award DE-SC0019443. Materials synthesis at the University of Washington (UW) was partially supported by the Gordon and Betty Moore Foundation's EPiQS Initiative, Grant GBMF6759 to JHC. Material characterization at UW was conducted at the Molecular Analysis Facility, a National Nanotechnology Coordinated Infrastructure (NNCI) site at the University of Washington with partial support from the National Science Foundation via awards NNCI-2025489 and NNCI-1542101. Material synthesis and characterization conducted by JY at Oak Ridge National Laboratory acknowledges support from the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. A portion of this work was performed at the National High Magnetic Field Laboratory, which is supported by the National Science Foundation Cooperative Agreement No. DMR-1644779, the State of Florida. We acknowledge the use of facility and instrumentation supported by the State of Washington through the University of Washington Clean Energy Institute. J.H.C. also acknowledges the support of the David and Lucile Packard Foundation.