Conventional spintronics exploit predominately the properties of ferromagnets (FM). The functionalities of the related devices suffer from two detrimental aspects including the stray fields and the gigahertz (GHz) spin dynamics. These intrinsic limits of FMs can be overcome in antiferromagnets (AFMs), resulting from their vanished stray field, and the faster dynamics in the terahertz (THz) range. On the other hand, AFMs are typically inert to the external magnetic fields. A reliable writing, and more importantly, an accurate read-out of these AFM states are often experimentally challenging, which impede their technological applications. By contrast, ferrimagnets (FIMs) exhibit two antiparallel lattices, and the magnetism of these two sublattices can be fully compensated that manifests as AFM-like dynamics. Unlike the weak resistive response of AFMs, the spin transport properties in FIMs is dominated by one particular lattice (or element). One can thus utilize the typical resistive measurements to unambiguously explore the ultrafast spin dynamics of FIMs. Based on the rare-earth iron garnets (RE₃Fe₅O₁₂), the rare earth-transition metal (RE-TM) alloys and the rare-earth-free nitrided manganese (Mn₄N), we will discuss the characteristic properties of the fully compensated ferrimagnetism and their resulting efficient spin dynamics. It is expected that the present review article could excite renowned interests in the compensated FIMs, which could be beneficial for developing the ultrafast spintronic memories and logics.

中文翻译：

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具有完全补偿的Ferrimagnets的高效自旋电子器件

常规自旋电子学主要利用铁磁体（FM）的特性。相关设备的功能遭受两个不利方面的影响，包括杂散场和千兆赫（GHz）自旋动力学。FM的这些固有限制可以用反铁磁体（AFM）克服，因为它们的杂散场消失了，太赫兹（THz）范围内的动力学更快。另一方面，原子力显微镜通常对外部磁场呈惰性。对这些原子力显微镜状态的可靠书写，更重要的是，准确读出这些信号通常在实验上具有挑战性，这阻碍了它们的技术应用。相比之下，亚铁（FIM）表现出两个反平行晶格，并且这两个子晶格的磁性可以得到完全补偿，表现为类似AFM的动力学。与AFM的弱电阻响应不同，FIM中的自旋输运特性受一个特定的晶格（或元素）支配。因此，人们可以利用典型的电阻测量来明确地探索FIM的超快自旋动力学。基于稀土铁石榴石（RE₃ Fe ₅ O ₁₂），稀土过渡金属（RE-TM）合金和不含稀土的氮化锰（Mn ₄ N），我们将讨论完全补偿的亚铁磁性的特征及其产生的有效自旋动力学。可以期望的是，这篇综述文章可能会引起人们对补偿型FIM的兴趣，这对于开发超快自旋电子存储器和逻辑将是有益的。