Wang Yu, Zhao Xinlei, Yao Li, Liu Huiru, Cheng Peng, Zhang Yiqi, Feng Baojie, Ma Fengjie, Zhao Jin, Sun Jiatao, Wu Kehui, Chen Lan
Institute of Physics, Chinese Academy of Sciences, Beijing, China.
School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China.
Nat Commun. 2024 Dec 30;15(1):10916. doi: 10.1038/s41467-024-55372-x.
Spin-polarized edge states in two-dimensional materials hold promise for spintronics and quantum computing applications. Constructing stable edge states by tailoring two-dimensional semiconductor materials with bulk-boundary correspondence is a feasible approach. Recently layered NiI is suggested as a two-dimensional type-II multiferroic semiconductor with intrinsic spiral spin ordering and chirality-induced electric polarization. However, the one-dimensional spin-polarized edge states of multiferroic materials down to monolayer limit has not yet been studied. We report here that monolayer NiI was successfully synthesized on Au(111) by molecular beam epitaxy. Spin-polarized scanning tunneling microscopy/spectroscopy experiments visualize orientation-selective spin-polarized edge states in monolayer NiI islands. By performing first-principles calculations, we further confirm that spin-polarized edge states are selectively aligning along the Ni-terminated edges rather than the I-terminated edges. Our result will provide the opportunity to tune edge states by selected orientation and to develop spintronic devices in two-dimensional magnetic semiconductors.
二维材料中的自旋极化边缘态在自旋电子学和量子计算应用方面具有潜力。通过利用体-边界对应关系来剪裁二维半导体材料以构建稳定的边缘态是一种可行的方法。最近，层状NiI被认为是一种具有本征螺旋自旋序和手性诱导极化的二维II型多铁性半导体。然而，多铁性材料直至单层极限的一维自旋极化边缘态尚未得到研究。我们在此报告，通过分子束外延在Au(111)上成功合成了单层NiI。自旋极化扫描隧道显微镜/能谱实验可视化了单层NiI岛中取向选择性的自旋极化边缘态。通过进行第一性原理计算，我们进一步证实自旋极化边缘态沿Ni端边缘而非I端边缘选择性排列。我们的结果将为通过选定取向调控边缘态以及在二维磁性半导体中开发自旋电子器件提供机会。
