  The intrinsic antiferromagnetic topological insulator MnBi2Te4 provides an
ideal platform for exploring exotic topological quantum phenomena. Recently,
the Chern insulator and axion insulator phases have been realized in few-layer
MnBi2Te4 devices at low magnetic field regime. However, the fate of MnBi2Te4 in
high magnetic field has never been explored in experiment. In this work, we
report transport studies of exfoliated MnBi2Te4 flakes in pulsed magnetic
fields up to 61.5 T. In the high-field limit, the Chern insulator phase with
Chern number C = -1 evolves into a robust zero Hall resistance plateau state.
Nonlocal transport measurements and theoretical calculations demonstrate that
the charge transport in the zero Hall plateau state is conducted by two
counter-propagating edge states that arise from the combined effects of Landau
levels and large Zeeman effect in strong magnetic fields. Our result
demonstrates the intricate interplay among intrinsic magnetic order, external
magnetic field, and nontrivial band topology in MnBi2Te4.
