压力可调的反常磁体La$_2$O$_3$Mn$_2$Se$_2$中的电子与磁子输运
Pressure-Tunable Electronic and Magnonic Transport in Altermagnet La$_2$O$_3$Mn$_2$Se$_2$
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中文总结 AI 辅助
该研究通过第一性原理计算与自旋哈密顿建模，发现静水压力可调控反常磁体La$_2$O$_3$Mn$_2$Se$_2$的交换各向异性，显著增强磁子自旋塞贝克响应并调控反常霍尔效应，为控制绝缘反常磁体的电子与磁子输运提供了新途径。
中文摘要 AI 辅助
静水压力为调控关联绝缘反常磁体La$_2$O$_3$Mn$_2$Se$_2$中的电子与磁子输运提供了一种保持对称性的途径。结合第一性原理计算与自旋哈密顿模型，我们发现0至40 GPa的压缩显著增强了竞争型次近邻交换相互作用的不等价性，使$|J_{2a}-J_{2b}|$从1.97 meV增大至9.38 meV，同时保持了补偿反铁磁基态。由此产生的交换各向异性放大了两支手性磁子分支间的动量依赖分裂，使100 K下纵向磁子驱动的自旋塞贝克响应提升近4倍，从$3.68\times10^{-1}$ meV/K增至1.36 meV/K。相反，静水压力在保持反常霍尔效应的磁对称性选择定则的同时，重新分布了电子贝里曲率，使反常霍尔电导率出现显著的能量依赖符号反转。这些结果确定了交换各向异性是压力增强磁子响应的微观机制，并确立静水压力为同时调控绝缘反常磁体中电子与磁子输运的有效手段。
英文摘要
Hydrostatic pressure provides a symmetry-preserving route to engineer electronic and magnonic transport in the correlated insulating altermagnet La$_2$O$_3$Mn$_2$Se$_2$. Using first-principles calculations combined with spin-Hamiltonian modeling, we show that compression from 0 to 40 GPa markedly enhances the inequivalence between the competing second-neighbor exchange interactions, increasing $|J_{2a}-J_{2b}|$ from 1.97 to 9.38 meV while preserving the compensated antiferromagnetic ground state. The resulting exchange anisotropy amplifies the momentum-dependent splitting between the two chiral magnon branches, yielding a nearly fourfold enhancement of the longitudinal magnon-driven spin Seebeck response at 100 K, from $3.68\times10^{-1}$ to $1.36$ meV/K. In contrast, hydrostatic pressure preserves the magnetic-symmetry selection rules governing the anomalous Hall effect while redistributing the electronic Berry curvature, producing pronounced energy-dependent sign reversals in the anomalous Hall conductivity. These results identify exchange anisotropy as the microscopic mechanism underlying the pressure-enhanced magnon response and establish hydrostatic pressure as an effective means of simultaneously controlling electronic and magnonic transport in insulating altermagnets.
