Jain Deepti, Yi Hee Taek, Yao Xiong, Mazza Alessandro R, Chen An-Hsi, Kisslinger Kim, Han Myung-Geun, Brahlek Matthew, Oh Seongshik
Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States.
Center for Quantum Materials Synthesis, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States.
Nano Lett. 2025 Mar 26;25(12):4720-4726. doi: 10.1021/acs.nanolett.4c05860. Epub 2025 Mar 13.
The intrinsic magnetic topological insulator (IMTI) family [MnTe][BiTe] has demonstrated magneto-topological properties dependent on , making it a promising platform for advanced electronics and spintronics. However, due to technical barriers in sample synthesis, their properties in the large limit remain unknown. To overcome this, we utilized the atomic layer-by-layer molecular beam epitaxy (ALL-MBE) technique and achieved IMTIs with as large as 15, far beyond that previously reported in bulk crystals or thin films. Then, we discover that the "single-layer magnet (SLM)" phase, primarily determined by intralayer ferromagnetic coupling, emerges for > ∼4 and remains little affected up to = 15. Nonetheless, still, nonzero, interlayer ferromagnetic coupling is necessary to stabilize the SLM phase, suggesting that the SLM phase eventually disappears in the → ∞ limit. This study uncovers the secrets of IMTIs beyond the thermodynamic limit and opens a door to diverse magneto-topological applications.
本征磁性拓扑绝缘体（IMTI）家族[MnTe][BiTe]已展现出依赖于 的磁拓扑性质，使其成为先进电子学和自旋电子学的一个有前景的平台。然而，由于样品合成中的技术障碍，它们在大 极限下的性质仍然未知。为克服这一问题，我们利用原子逐层分子束外延（ALL-MBE）技术，实现了高达15的 ，远超此前在体晶体或薄膜中报道的数值。然后，我们发现，主要由层内铁磁耦合决定的“单层磁体（SLM）”相，在 ＞ ∼4时出现，并且在 = 15之前几乎不受影响。尽管如此，仍然需要非零的层间铁磁耦合来稳定SLM相，这表明SLM相最终在 → ∞极限下消失。本研究揭示了超越热力学极限的IMTI的秘密，并为各种磁拓扑应用打开了一扇门。
