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arXiv · 2603.11305

Intrinsic Even-Odd Thickness-Driven Anomalous Hall in Epitaxial MnBi2Te4 Thin Films

Debarghya Mallick·Simon Kim·An-Hsi Chen·Gabriel A. Vázquez-Lizardi·Alessandro R. Mazza·T. Zac Ward·Gyula Eres·Yue Cao·Debangshu Mukherjee·Hu Miao·Liang Wu·Christopher Nelson·Danielle Reifsnyder Hickey·Robert G. Moore·Matthew Brahlek
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Abstract

We demonstrate precise control of magnetism in MnBi2Te4 thin films through careful synthesis by molecular beam epitaxy, achieving minimal defects and accurate layer thickness control. By optimizing Mn-Bi-Te ratios and growth temperatures, we minimize detrimental self-doping effects and accurately target integer-layer films. X-ray diffraction and reflectivity provide quantitative measures of film quality and thickness. When these macroscale probes of structure and thickness are integrated with magnetotransport measurements, a striking even-odd layer dependence of the anomalous Hall effect is revealed. Odd-layer films exhibit a large hysteresis up to the N\'eel temperature (~25K), consistent with non-compensated antiferromagnetism, while even-layer films show minimal response, as expected for an antiferromagnet. The sign of the anomalous Hall effect exhibits a sign reversal for intrinsic magnetism versus magnetism associated with defects. This work identifies critical factors for inducing pure, non-compensated ferromagnetism and reveals the character of the intrinsic anomalous Hall effect in MnBi2Te4, which together is a step towards realizing the zero-field quantum anomalous Hall effect in topological materials.

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Debarghya Mallick, Simon Kim, An-Hsi Chen, Gabriel A. Vázquez-Lizardi, Alessandro R. Mazza, T. Zac Ward, Gyula Eres, Yue Cao, Debangshu Mukherjee, Hu Miao, Liang Wu, Christopher Nelson, Danielle Reifsnyder Hickey, Robert G. Moore, Matthew Brahlek. 2026-03-11. Intrinsic Even-Odd Thickness-Driven Anomalous Hall in Epitaxial MnBi2Te4 Thin Films. https://arxiv.org/abs/2603.11305

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