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arXiv · 2001.10579

Observation of high-temperature quantum anomalous Hall regime in intrinsic MnBi$_2$Te$_4$/Bi$_2$Te$_3$ superlattice

Haiming Deng·Zhiyi Chen·Agnieszka Wolos·Marcin Konczykowski·Kamil Sobczak·Joanna Sitnicka·Irina V. Fedorchenko·Jolanta Borysiuk·Tristan Heider·Lukasz Plucinski·Kyungwha Park·Alexandru B. Georgescu·Jennifer Cano·Lia Krusin-Elbaum
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Abstract

The quantum anomalous Hall effect is a fundamental transport response of a topologically non-trivial system in zero magnetic field. Its physical origin relies on the intrinsically inverted electronic band structure and ferromagnetism, and its most consequential manifestation is the dissipation-free flow of chiral charge currents at the edges that can potentially transform future quantum electronics. Here we report a previously unknown Berry-curvature-driven anomalous Hall regime ('Q-window') at above-Kelvin temperatures in the magnetic topological bulk crystals where through growth Mn ions self-organize into a period-ordered MnBi$_2$Te$_4$/Bi$_2$Te$_3$ superlattice. Robust ferromagnetism of the MnBi$_2$Te$_4$ monolayers opens a large surface gap, and anomalous Hall conductance reaches an $e^2/h$ quantization plateau when the Fermi level is tuned into this gap within a Q-window in which the anomalous Hall conductance from the bulk is to a high precision zero. The quantization in this new regime is not obstructed by the bulk conduction channels and thus should be present in a broad family of topological magnets.

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Haiming Deng, Zhiyi Chen, Agnieszka Wolos, Marcin Konczykowski, Kamil Sobczak, Joanna Sitnicka, Irina V. Fedorchenko, Jolanta Borysiuk, Tristan Heider, Lukasz Plucinski, Kyungwha Park, Alexandru B. Georgescu, Jennifer Cano, Lia Krusin-Elbaum. 2020-01-28. Observation of high-temperature quantum anomalous Hall regime in intrinsic MnBi$_2$Te$_4$/Bi$_2$Te$_3$ superlattice. https://doi.org/10.1038/s41567-020-0998-2

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