Fragile unconventional magnetism in RuO 2 by proximity to Landau-Pomeranchuk instability

作者：Zhuang Qian, Yudi Yang, Shi Liu, Congjun Wu · 发表于：Physical review. B./Physical review. B · 年份：2025 · DOI：10.1103/physrevb.111.174425 · 被引用次数：23 · 研究领域：Advanced Condensed Matter Physics、Magnetic and transport properties of perovskites and related materials、Theoretical and Computational Physics

Altermagnetism has attracted considerable attention for its remarkable combination of spin-polarized band structures and zero net magnetization, making it a promising candidate for spintronics applications. We demonstrate that this magnetic phase represents a case of unconventional magnetism, first proposed nearly two decades ago by one of the present authors as part of a broader framework for understanding Landau-Pomeranchuk instabilities in the spin channel, driven by many-body interactions. By systematically analyzing the altermagnetism in ${\mathrm{RuO}}_{2}$ with first-principles calculations, we reconcile conflicting experimental and theoretical reports by attributing it to ${\mathrm{RuO}}_{2}$'s proximity to a quantum phase transition. We emphasize the critical role of tuning parameters, such as the Hubbard $U$, hole doping, and epitaxial strain, in modulating quasiparticle interactions near the Fermi surface. This work provides fresh insights into the origin and tunability of altermagnetism in ${\mathrm{RuO}}_{2}$, highlighting its potential as a platform for investigating quantum phase transitions and the broader realm of unconventional magnetism.