AI 中文总结
本文研究磁场调控易平面d波altermagnets的热自旋输运，以NiF₂为例证明其磁振子磁矩的d波对称性及自旋分裂效应，且垂直易平面的外磁场可有效调控热自旋电导率。
AI 中文摘要
Altermagnets 是一类新型共线自旋补偿材料，其磁振子分支在非相对论极限下也会发生自旋分裂，这源于连接两个子晶格的对称操作比常规反铁磁体更复杂。Altermagnetic 分裂会显著影响磁振子输运性质，尤其在易轴 d 波 altermagnets 中会产生热磁振子分裂效应。易平面体系中是否存在该效应尚不明确，因为此类体系中磁振子分支不携带恒定磁矩。本文以金红石型易平面 d 波 altermagnet（如 NiF₂）为研究对象，证明了 altermagnet 产生的磁振子磁矩具有动量依赖性和 d 波对称性，进而产生自旋分裂效应，即在外加温度梯度下会出现磁振子驱动的自旋电流（磁矩流）。研究还表明，垂直于易平面的外磁场可有效调控对应的热自旋电导率。
英文摘要
Altermagnets constitute a novel class of collinear spin-compensated materials in which magnon branches are spin-split even in the non-relativistic limit. The latter is the result of a more complex symmetry operation (compared to conventional antiferromagnets) that connects the two sublattices. Altermagnetic splitting strongly affects the magnon transport properties, leading, in particular, to the thermal magnon splitter effect in easy-axial $d$-wave altermagnets. Whether this effect also appears in easy-planar systems is not obvious, since the magnon branches do not carry a constant magnetic moment in this case. Here, we consider the easy-planar $d$-wave altermagnet of a rutile-type, e.g., NiF$_2$, and demonstrate the emergence of the altermagnetically generated magnon magnetic moment, which is momentum-dependent and possesses $d$-wave symmetry. This then leads to the spin-splitter effect, i.e., the emergence of a magnon-driven spin current (the flow of magnetic moment) in response to the applied temperature gradient. We also demonstrate that the corresponding thermal spin conductivity can be effectively tuned by an external magnetic field perpendicular to the easy plane.
Comments11 pages, 8 figures
