Growth, characterization, and Chern insulator state in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>MnBi</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>Te</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math> via the chemical vapor transport method
Chaowei Hu, Anyuan Gao, Bryan S. Berggren, Hong Li, R. Kurleto, Dushyant Narayan, Ilija Zeljkovic, Dan Dessau, Su‐Yang Xu, Ni Ni
Abstract
As the first intrinsic antiferromagnetic topological insulator, ${\mathrm{MnBi}}_{2}{\mathrm{Te}}_{4}$ has provided a platform to investigate the interplay of band topology and magnetism as well as the emergent phenomena arising from such an interplay. Here we report the chemical-vapor-transport (CVT) growth and characterization of ${\mathrm{MnBi}}_{2}{\mathrm{Te}}_{4}$, as well as the observation of the field-induced quantized Hall conductance in 6-layer devices. Through comparative studies between our CVT-grown and flux-grown ${\mathrm{MnBi}}_{2}{\mathrm{Te}}_{4}$ via magnetic, transport, scanning tunneling microscopy, and angle-resolved photoemission spectroscopy measurements, we find that CVT-grown ${\mathrm{MnBi}}_{2}{\mathrm{Te}}_{4}$ is marked with higher Mn occupancy on the Mn site, slightly higher ${\mathrm{Mn}}_{\mathrm{Bi}}$ antisites, smaller carrier concentration, and a Fermi level closer to the Dirac point. Furthermore, a 6-layer device made from the CVT-grown sample shows by far the highest mobility of 2500 ${\mathrm{cm}}^{2}\phantom{\rule{0.16em}{0ex}}\mathrm{V}\phantom{\rule{0.16em}{0ex}}\mathrm{s}$ in ${\mathrm{MnBi}}_{2}{\mathrm{Te}}_{4}$ devices with the quantized Hall conductance appearing at 1.8 K and 8 T. Our study provides a route to obtain high-quality single crystals of ${\mathrm{MnBi}}_{2}{\mathrm{Te}}_{4}$ that are promising to make superior devices and realize emergent phenomena, such as the layer Hall effect and quantized anomalous Hall effect, etc.