2025/10/15 by Zheng Wang, Wang, Zheng, Bo Ruan +7
Materials Science · Physics and Astronomy · #Chemical and Physical Properties of Materials #Computational Physics (physics.comp-ph) #FOS: Physical sciences #Graphene research and applications #Materials Science (cond-mat.mtrl-sci) #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.2510.13107
openalex publication_date 2025/10/15 · openalex created_date 2025/10/17 · openalex updated_date 2026/07/28
The quest for robust, intrinsically magnetic topological materials exhibiting the quantum anomalous Hall (QAH) effect is a central challenge in condensed matter physics and the application of revolutionary electronics. However, progress has been hampered by the limited number of candidate materials, which often suffer from poor stability and complex synthesis. Here, we introduce a new paradigm by exploring the emergent magnetism and nontrivial band topology in the largely overlooked family of two-dimensional (2D) pentagonal MN8 monolayers. Employing first-principles calculations, we reveal that these systems host out-of-plane ferromagnetic ground states, a key feature that unlocks nontrivial topological properties driven by the localized d-orbitals of the embedded transition metals. Remarkably, we identify TiN8 as a QAH insulator characterized by a Chern number of C=-1. Even more strikingly, MoN8 is predicted to be a rare high-Chern-number QAH insulator, boasting a Chern number of C=2. Our findings establish the penta-MN8 family as a fertile and versatile platform for realizing exotic topological quantum states. This work not only significantly expands the material landscape for magnetic topological insulators but also provides a solid theoretical foundation for designing next-generation spintronic and quantum computing devices.