Single femtosecond-pulse toggle switching of ferrimagnetic alloys is an essential building block for ultrafast spintronics. It is believed that for switching to occur in these ferrimagnets, the individual sublattices must have very different (element-specific) demagnetization dynamics. This suggests that ferrimagnets composed of two different elements, such as rare-earth transition-metal alloys, are necessary for switching. However, experimental observations of toggle switching in the Heusler alloy Mn2Ru xGa, which has two crystallographically nonequivalent Mn sublattices with antiparallel aligned moments, have questioned these assertions. To shed some light on this question, we present an atomistic spin model for the simulation of single pulse toggle switching of Mn2Ru xGa. The magnetic parameters entering our model are extracted from previous experimental observations. We show that our model is able to quantitatively reproduce the experimentally measured magnetization dynamics of single pulse toggle switching. We demonstrate that toggle switching in Mn2Ru xGa is possible even when both Mn sublattices demagnetize at very similar rates, in contradiction to the previous hypothesis about the importance of element-specific demagnetization rates in this process.

中文翻译：

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Mn2RuxGa Heusler 合金中单脉冲切换的原子自旋模型

亚铁磁合金的单飞秒脉冲切换开关是超快自旋电子学的重要组成部分。据信，为了在这些亚铁磁体中发生切换，各个子晶格必须具有非常不同的（特定于元素的）退磁动力学。这表明由两种不同元素组成的亚铁磁体，例如稀土过渡金属合金，对于切换是必需的。然而，Heusler 合金 Mn 中拨动开关的实验观察2个汝XGa 具有两个晶体学上不等效的 Mn 子晶格，具有反平行排列的力矩，质疑了这些断言。为了阐明这个问题，我们提出了一个原子自旋模型来模拟 Mn 的单脉冲切换2个汝XGa. 进入我们模型的磁参数是从以前的实验观察中提取的。我们表明，我们的模型能够定量地再现实验测量的单脉冲切换的磁化动力学。我们证明了 Mn 中的切换开关2个汝X即使两个 Mn 亚晶格以非常相似的速率退磁，Ga 也是可能的，这与之前关于元素特定退磁率在此过程中的重要性的假设相矛盾。