iAFMskyrmions - Intrinsic antiferromagnetic skyrmions from first-principles: stabilization, interaction with defects and efficient detection

铁磁（FM）skyrmions已被发现在大量的材料。它们作为未来信息技术的比特的使用受到它们与缺陷的复杂相互作用、杂散场的存在（这限制了它们的小型化）以及由于Skyrmion Hall效应而难以控制它们的轨迹的阻碍。这些问题预计将在反铁磁（AFM）skyrmions，它提供了几个优点，虽然是不平凡的检测解决。到目前为止，这些已经稳定在合成AFM结构，即多层托管FM skyrmions，通过非磁性间隔物反铁磁耦合。在这个建议中，我们的目标是在第一性原理预测的内在AFM skyrmions出现在薄膜。我们的初步工作已经表明，稳定的亚10纳米原子力显微镜skyrmions和其他拓扑自旋纹理的元素的正确选择的可能性。基于密度泛函理论（DFT），含时DFT和多重散射概念，我们计划对不同材料组合进行系统的第一性原理研究，并探索引发复杂AFM拓扑自旋纹理的各种旋钮，重点关注：（i）量子和热涨落，我们预计这在反铁磁体中很重要;（ii）我们最近发现的高阶多自旋手征相互作用;（iii）基于手性轨道磁性、自旋混合磁阻和基于多位点多自旋相互作用的新机制的检测协议;（iv）AFMskyrmion缺陷相互作用和潜在电子机制的系统编目。针对通用模式的识别，我们推测，缺陷工程（选定类型的缺陷的控制位置）是有用的高效检测，表征和操作的AFM skyrmions。我们计划与Würzburg小组（Bode）合作，目标是用STM测量来探索AFM skyrmions，与MPI Halle（Parkin）合作研究skyrmions和antiskyrmions的各个方面，与TUM（Back）合作研究skyrmions的动力学，与Konstanz/Mainz小组（Nowak/Levente/Kläui）合作研究AFM自旋纹理的第一原理描述。

Ferromagnetic (FM) skyrmions have been discovered in a plethora of materials. Their use as future bits for information technology is hindered by their complex interaction with defects, the presence of stray fields, which limit their miniaturization, and the difficulty to control their trajectory due to the skyrmion Hall effect. These issues are expected to resolve in antiferromagnetic (AFM) skyrmions, which offer several advantages although being not-trivial to detect. So far these have been stabilized in synthetic AFM structures, i.e. multilayers hosting FM skyrmions, which couple antiferromagnetically through a non-magnetic spacer. In this proposal, we aim at the first-principles prediction of intrinsic AFM skyrmions emerging in thin films. Our preliminary work already shows the possibility of stabilizing sub-10 nm AFM skyrmions and other topological spin-textures with the right choice of elements. Hinging on density functional theory (DFT), time-dependent DFT, and multiple-scattering concepts, we plan systematic first-principles investigations of diverse combinations of materials and explore various knobs triggering complex AFM topological spin-textures focusing on: (i) quantum and thermal fluctuations, which we expect to be important in antiferromagnets; (ii) high-order multi-spin chiral interactions that we recently unveiled; (iii) detection protocols based on chiral orbital magnetism, spin-mixing magnetoresistance, and new mechanisms based on multi-site multi-spin interactions; (iv) systematic cataloging of AFMskyrmion-defect interactions and the underlying electronic mechanisms. Aiming at the identification of universal patterns, we conjecture that defect-engineering (controlled placement of selected types of defects) is useful for efficient detection, characterization, and manipulation of AFM skyrmions. We plan collaborations with the Würzburg group (Bode) having the goal of prospecting AFM skyrmions with STM measurements, with MPI-Halle (Parkin) on various aspects of skyrmions and antiskyrmions, with TUM (Back) on dynamics of skyrmions and with Konstanz/Mainz groups (Nowak/Levente/Kläui) on first-principles description of AFM spin-textures.