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.
@article{arxiv.2603.11305,
title = {Intrinsic Even-Odd Thickness-Driven Anomalous Hall in Epitaxial MnBi2Te4 Thin Films},
author = {Debarghya Mallick and Simon Kim and An-Hsi Chen and Gabriel A. Vázquez-Lizardi and Alessandro R. Mazza and T. Zac Ward and Gyula Eres and Yue Cao and Debangshu Mukherjee and Hu Miao and Liang Wu and Christopher Nelson and Danielle Reifsnyder Hickey and Robert G. Moore and Matthew Brahlek},
journal= {arXiv preprint arXiv:2603.11305},
year = {2026}
}