AI 中文总结
研究RuO₂磁基态争议问题，通过第一性原理计算表明其磁性可在TiO₂/RuO₂界面以边界相出现，揭示界面电子重构等，发现对称异质结构中两磁性界面耦合产生厚度依赖状态交替，表明界面工程可稳定控制RuO₂磁性。
AI 中文摘要
交替磁体候选材料RuO₂的磁基态仍存在争议，其磁特征主要在外延薄膜中观察到。本文通过第一性原理计算表明，外延RuO₂中的磁性可作为TiO₂/RuO₂界面处的界面边界相出现。仅TiO₂诱导的外延应变不会使（001）取向的RuO₂具有磁性，但明确的TiO₂/RuO₂界面能稳定局限于前几层Ru的可观Ru磁矩。电荷密度和轨道分辨分析揭示了界面电子重构，且衬底掺杂提供了调节诱导磁矩的途径。在对称TiO₂/RuO₂/TiO₂异质结构中，两个磁性界面通过金属RuO₂间隔层耦合，产生与厚度相关的弱铁磁和补偿交替磁状态的交替。结果表明界面工程是稳定和控制RuO₂中脆弱磁性的实用途径。
英文摘要
The magnetic ground state of the altermagnet candidate RuO$_2$ remains controversial, with magnetic signatures observed mainly in epitaxial films. Here we show, using first-principles calculations, that magnetism in epitaxial RuO$_2$ can emerge as an interfacial boundary phase at TiO$_2$/RuO$_2$ interfaces. While TiO$_2$-induced epitaxial strain alone does not make (001)-oriented RuO$_2$ magnetic, explicit TiO$_2$/RuO$_2$ interfaces stabilize sizable Ru moments confined to the first few Ru layers. Charge-density and orbital-resolved analyses reveal interfacial electronic reconstruction, and substrate doping provides a route to tune the induced moments. In symmetric TiO$_2$/RuO$_2$/TiO$_2$ heterostructures, the two magnetic interfaces couple through the metallic RuO$_2$ spacer, producing a thickness-dependent alternation between weak-ferromagnetic and compensated altermagnetic states. Our results identify interface engineering as a practical route to stabilize and control fragile magnetism in RuO$_2$.
