磁性材料，特別是鐵磁半導體，可以與現代半導體工藝進行集成，因此往往被認為是自旋電子學領域中的理想材料。除了本征磁性半導體外，過渡金屬摻雜的稀磁半導體也得到廣泛研究。另外，不含d/f電子的室溫d⁰鐵磁半導體也是磁性材料研究的一個重要分支。由于空穴媒介作用被認為是“d⁰鐵磁性”的起源，且可以通過摻雜甚至缺陷來實現，這種“d⁰鐵磁性”為尋找高溫自旋電子材料提供了不同的方案與可能性。與此同時，在過去十年里，二維本征鐵磁材料也快速發展，甚至已有一些自旋隧道結的測量研究。

然而，二維本征鐵磁材料十分缺乏，且它們普遍擁有較低的居里溫度，不利于低維自旋電子學器件的發展與應用。近年來研究者逐漸將目光移至摻雜誘導的二維d⁰鐵磁半導體，但是系統的研究依舊缺乏，且自旋極化空穴的交換耦合與非局域化機制尚不清晰。

來自荷語魯汶大學物理天文學院的Ruishen Meng教授與Michel Houssa教授合作，從三個主流數據庫中篩選了數千個二維非磁半導體，并借助高通量密度泛函理論計算，確定出了空穴摻雜引起磁性的潛在候選材料。

他們對材料進行了穩定性計算，最終確定出122種穩定的二維材料。這些材料均可以由空穴摻雜實現穩定的磁有序，并且部分體系的居里溫度達到了室溫。最后，他們還討論了鐵磁有序的交換相互作用。

該工作大大豐富了二維磁性材料庫，同時對空穴摻雜誘導鐵磁材料提供了一定的理論見解，為將來實現二維自旋電子器件打下了一定基礎。相關論文近期發布于npj Computational Materials 8: 230 (2022)。

Editorial Summary

Magnetic materials, especially ferromagnetic semiconductors, are considered advantageous in the field of spintronics because of their easy integration into semiconductor devices. Apart from the intrinsic magnetic materials, research attention has also been focusing on dilute magnetic semiconductors (DMSs). Besides, room temperature d⁰FM semiconductor without d/f electrons is also an important branch of magnetic materials. As hole mediation is considered to be the origin of the ‘d⁰ferromagnetism’, which can be realized by acceptor doping or even by intrinsic defects, the ‘d⁰ ferromagnetism’ offers a different way and possibility to hunt for high-temperature spintronic materials. Meanwhile, the past decade has witnessed the rapid development of 2D magnetic materials and even 2D tunneling junctions. However, the scarcity of 2D FM semiconductors and their rather low Curie temperature (Tc) hamper practical applications as well as the further investigation of 2D magnetism. In the recent years, studies have predicted several (hole-)doping induced 2D d⁰ FM semiconductors. However, a systematic investigation of the magnetic properties of these 2D materials is still lacking. The mechanism responsible for the exchange coupling and delocalization of the spin-polarized holes has not been discussed yet.?

A team led by Prof. Ruishen Meng and Prof. Michel Houssa from the Department of Physics and Astronomy in KU Leuven Celestijnenlaan 200D, screened thousands of 2D non-magnetic semiconductors/insulators from three databases, and performed a high-throughput density functional theory calculation to identify potential 2D FM materials induced by hole doping. They then verified the stability of the potential candidates, for which 122 materials were recognized as stable 2D FM materials upon hole doping. The computed Curie temperatures of some systems were close to or above room temperature. At last, the exchange interaction mechanisms responsible for the FM coupling in these 2D materials were also discussed. This work not only provides theoretical insights into hole-doped 2D FM materials, but also enriches the family of 2D magnetic materials for possible spintronic applications, laying a certain foundation for the realization of two-dimensional spintronic devices in the future. This article was recently published in npj Computational Materials 8: 230 (2022).

原文Abstract機器翻譯

Abstract?Two-dimensional (2D) ferromagnetic materials are considered as promising candidates for the future generations of spintronic devices. Yet, 2D materials with intrinsic ferromagnetism are scarce. Hereby, high-throughput first-principles simulations are performed to screen 2D materials that present a non-magnetic to a ferromagnetic transition upon hole doping. A global evolutionary search is subsequently performed to identify alternative possible atomic structures of the eligible candidates, and 122 materials exhibiting a hole-doping induced ferromagnetism are identified. Their energetic and dynamic stability, as well as magnetic properties under hole doping are investigated systematically. Half of these 2D materials are metal halides, followed by chalcogenides, oxides, and nitrides, some of them having predicted Curie temperatures above 300?K. The exchange interactions responsible for the ferromagnetic order are also discussed. This work not only provides theoretical insights into hole-doped 2D ferromagnetic materials, but also enriches the family of 2D magnetic materials for possible spintronic applications.

摘要二維（2D）鐵磁材料是未來建構自旋電子器件有前途的候選材料。然而，具有本征鐵磁性的二維材料相當稀缺。在此，通過高通量第一性原理模擬，我們篩選出了一系列二維材料，它們會在空穴摻雜條件下呈現出非磁性到鐵磁序的轉變。隨后，我們進行了全局演化搜索其他可能的結構，最終確定了122種表現出空穴摻雜誘導鐵磁性的二維材料。我們系統地研究了它們在摻雜時的能量和動力學穩定性以及磁學性質。這些二維材料有一半是金屬鹵化物，其次是硫族化合物、氧化物和氮化物，其中一些材料的居里溫度可以超過300 K。我們還討論了鐵磁序相關的交換相互作用。這項工作不僅為空穴摻雜的二維鐵磁材料提供了理論見解，而且大大豐富了二維磁性材料家族，有望實現自旋電子器件應用。