Higher-Order Topological Phase in the Two-Dimensional Type-IV Magnet MgCr$_2$O$_4$

[2608.27918] Higher-Order Topological Phase in the Two-Dimensional Type-IV Magnet MgCr$_2$O$_4$ Skip to main content Search Submit Donate Log in Physics > Computational Physics arXiv:2608.27918 (physics) [Submitted on 28 Aug 2026] Title: Higher-Order Topological Phase in the Two-Dimensional Type-IV Magnet MgCr$_2$O$_4$ Authors: Xiaorong Zou , Hyeon Suk Shin , Yanmei Zang , Ying Dai , Chengwang Niu , Chang-Jong Kang , Chang Woo Myung View PDF HTML (experimental) Abstract: Type-IV two-dimensional (2D) magnetism-a newly classified collinear magnetic phase featuring nonrelativistic spin degeneracy and spin-orbit-coupling-induced momentum-dependent spin splitting-extends the symmetry classification of collinear magnets, opening new opportunities for unconventional topological quantum states. Here, we reveal that the recently proposed two-dimensional type-IV 2D magnet MgCr$_2$O$_4$ hosts an intrinsic higher-order topological insulating phase, featuring $\mathcal{C}_{3z}$-protected corner states and a nontrivial rotational topological invariant of $\chi^{(3)}$ = $\{-2,4\}$ with a quantized fractional corner charge of $4e/3$. Spin-orbit coupling breaks the spin-degeneracy-enforcing symmetry $[C_{2}||M_z]$ while preserving the crystalline $\mathcal{C}_{3z}$ rotational symmetry that protects the higher-order topological phase, thereby enabling spin splitting to coexist with the nontrivial topology. Furthermore, the higher-order topological phase remains intact throughout a wide range of biaxial strains without band-gap closing and topological phase transition, demonstrating the robustness of the symmetry-protected topological state against external perturbations. Our work establishes a direct connection between type-IV magnetic system and higher-order topology, providing a new route for symmetry-engineered magnetic topological quantum states. Comments: 4 figures Subjects: Computational Physics (physics.comp-ph) Cite as: arXiv:2608.27918 [physics.comp-ph] (or arXiv:2608.27918v1 [physics.comp-ph] for this version) https://doi.org/10.48550/arXiv.2608.27918 Focus to learn more arXiv-issued DOI via DataCite Submission history From: Chang Woo Myung [ view email ] [v1] Fri, 28 Aug 2026 04:45:57 UTC (4,959 KB) Full-text links: Access Paper: View PDF HTML (experimental) TeX Source view license Current browse context: physics.comp-ph < prev | next > new | recent | 2026-08 Change to browse by: physics References & Citations NASA ADS Google Scholar Semantic Scholar export BibTeX citation Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer ( What is the Explorer? ) Connected Papers Toggle Connected Papers ( What is Connected Papers? ) Litmaps Toggle Litmaps ( What is Litmaps? ) scite.ai Toggle scite Smart Citations ( What are Smart Citations? ) Code, Data, Media Code, Data and Media Associated with this Article alphaXiv Toggle alphaXiv ( What is alphaXiv? ) Links to Code Toggle CatalyzeX Code Finder for Papers ( What is CatalyzeX? ) DagsHub Toggle DagsHub ( What is DagsHub? ) GotitPub Toggle Gotit.pub ( What is GotitPub? ) Huggingface Toggle Hugging Face ( What is Huggingface? ) ScienceCast Toggle ScienceCast ( What is ScienceCast? ) Demos Demos Replicate Toggle Replicate ( What is Replicate? ) Spaces Toggle Hugging Face Spaces ( What is Spaces? ) Spaces Toggle TXYZ.AI ( What is TXYZ.AI? ) Related Papers Recommenders and Search Tools Link to Influence Flower Influence Flower ( What are Influence Flowers? ) Core recommender toggle CORE Recommender ( What is CORE? ) Author Venue Institution Topic About arXivLabs arXivLabs: experimental projects with community collaborators arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website. Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. arXiv is committed to these values and only works with partners that adhere to them. Have an idea for a project that will add value for arXiv's community? Learn more about arXivLabs . Which authors of this paper are endorsers? | Disable MathJax ( What is MathJax? ) We gratefully acknowledge support from our major funders , member institutions , and all contributors. About · Help · Contact · Subscribe · Copyright · Privacy · Accessibility · Operational Status (opens in new tab) Major funding support from

Related documents

• Higher-Order Topological Phase in the Two-Dimensional Type-IV Magnet MgCr$_2$O$_4$#779821
• AlterSeeK-Path: Systematic construction of generalized band-structure paths for displaying altermagnetic spin splitting#924899
• AlterSeeK-Path: Systematic construction of generalized band-structure paths for displaying altermagnetic spin splitting#920665
• Magnetic frustration and non-collinear textures in layered Gd magnets#819611
• Magnetic frustration and non-collinear textures in layered Gd magnets#809615