二维多铁异质结构中的铁电可控自旋轨道转矩
Ferroelectric-controllable spin-orbit torque in two-dimensional multiferroic heterostructure
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中文总结 AI 辅助
本研究以Fe₃GeTe₂/In₂Se₃异质结构为对象，通过第一性原理计算发现铁电极化可调控自旋轨道转矩，为可编程自旋电子器件提供了可行方案。
中文摘要 AI 辅助
自旋轨道转矩（SOT）可实现对磁化强度的电学调控，在下一代自旋电子器件的研发中发挥着关键作用。在二维范德华体系中实现自旋轨道转矩，同时通过铁电性实现高效的非易失性调控，对于构建存储密度更高的可调谐逻辑器件具有重要意义。本研究基于第一性原理计算，以多铁Fe₃GeTe₂/In₂Se₃异质结构为典型示例，证明In₂Se₃层的铁电极化翻转会显著改变异质结构中与磁化强度相关的转矩分布。具体而言，当磁化强度处于平面内（此时转矩最大）时，将In₂Se₃的极化方向从向上翻转为向下，总转矩会提升至原有值的150%以上。这一显著变化主要源于极化诱导的时间反演奇异性转矩的z分量调制，该调制与Fe₃GeTe₂层中中间Fe原子层贡献的原子分辨转矩发生约233%的变化直接相关。进一步分析表明，费米面上Γ点附近的电子态在极化翻转时会发生显著重构，这是观测到的时间反演奇异性转矩变化的根源。本研究结果不仅为范德华多铁异质结构的功能潜力提供了新的见解，还为实现电学可调谐自旋轨道转矩提供了可行策略，为未来可编程自旋电子器件的研发铺平了道路。
英文摘要
Spin-orbit torque (SOT), which enables electrical control of magnetization, plays a crucial role in the development of next-generation spintronic devices. Realizing SOT in two-dimensional van der Waals systems, together with achieving efficient nonvolatile manipulation via ferroelectricity, would be highly beneficial for the implementation of tunable logic devices with enhanced storage density. In this work, based on first-principles calculation and using a multiferroic Fe$_{3}$GeTe$_{2}$/In$_{2}$Se$_{3}$ heterostructure as a representative example, we demonstrate that switching the ferroelectric polarization of the In$_{2}$Se$_{3}$ layer induces a pronounced modification in the magnetization-dependent distribution of torkance within the heterostructure. Specifically, when the magnetization is in the plane, where the torque is maximal, reversing the polarization of In$_{2}$Se$_{3}$ from upward to downward enhances the total torkance to more than 150% of its original value. This substantial variation primarily originates from the polarization-induced modulation of the $z$ component of the time-reversal-odd torkance, which is mainly associated with an approximately 233% change in the atomic-resolved torque contributed from the middle Fe layer in Fe$_{3}$GeTe$_{2}$ layer. Further analysis reveals that the electronic states near $Γ$ on the Fermi surface undergo significant reconstruction upon polarization switching, which is responsible for the observed variation in the time-reversal-odd torque. Our results not only provide new insights into the functional potential of van der Waals multiferroic heterostructures, but also offer a viable strategy for achieving electrically tunable SOT, paving the way for future programmable spintronic devices.
