Chiral Spin Textures in Magnetic Nanostructures

磁性纳米结构中的手性自旋纹理

• 批准号: 2005108
• 负责人: Kai Liu
• 金额: $ 51.98万
• 依托单位: Georgetown University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2005108&HistoricalAwards=false
• 关键词: Chiral; Spin; Textures; Magnetic; Nanostructures

Nontechnical Abstract:Magnetic moments in magnets can form various configurations known as spin textures, such as domain walls where the moments form a winding configuration connecting adjacent domains with different magnetization directions. Usually, the rotational sense of the moments in spin textures is expected to be achiral, where the left- and right-handed rotations are equally possible. In certain magnetic thin films, the broken inversion symmetry of atomic structure at the interface between magnetic and heavy metal layers leads to an interfacial effect which lifts the chiral degeneracy and stabilizes chiral spin structures such as spin spirals, chiral domain walls or magnetic skyrmions. These chiral spin textures exhibit a preferred handedness and fascinating topological characteristics. Their extraordinary properties provide new insights into fundamental problems of magnetism and exciting potentials for novel magnetic technologies. This project aims at significantly advancing the field by unlocking a number of degrees of freedom for a better understanding and control of such spin textures. Several novel spin textures are investigated, including exotic types of skyrmions and chiral domain walls in 2-dimensional thin films and topological spin textures such as Mobius bands in 3-dimensional magnetic structures. They have the potential to fundamentally transform the energy landscape for future information storage. This project provides valuable training opportunities for students in university as well as national laboratory and other facilities. The principal investigator actively engages in a variety of efforts to broaden participation from underrepresented groups through course offering, public lectures, exchange visits, and professional conference organization.Technical Abstract:Chiral spin textures are investigated to demonstrate a number of new degrees of freedom to better control them, including antiskyrmion Hall angle, topological number, chemisorbed species, and 3-dimensional topological configuration. Anisotropic Dzyaloshinskii-Moriya interaction is utilized to stabilize antiskyrmions in magnetic thin films. The antiskyrmion Hall angle is explored for controlling skyrmion trajectory or topological sorting, which can be potentially used for designing complex skyrmionics devices. High winding number skyrmions are demonstrated, which unlocks the topological number as a new degree of freedom that may support novel topological functionalities in logic devices. Effects of chemisorbed species under vacuum onto ferromagnet films are studied to induce chiral domain walls and enable direct writing of skyrmions without magnetic or electric fields. Chemisorptions of low atomic number atoms and organic molecules are studied to induce reversible switching of magnetic chirality and tuning of perpendicular magnetic anisotropy. Novel types of 3-dimensional topological spin textures such as Mobius bands are fabricated and their topological characters are investigated. These novel spin textures offer new mechanisms for robust and low dissipation information storage, which is well aligned with grand challenges for future nanoelectronics. This project includes a wide variety of efforts to broaden participation from underrepresented groups. Students involved receive excellent exposure to research experience in academia, government laboratory and other research facilities.This DMR grant supports research on chiral spin structure in magnetic nanoparticles with funding from the Condensed Matter Physics (CMP) and the Electronic and Photonic Materials (EPM) Programs in the Division of Materials Research of the Mathematical and Physical Sciences Directorate.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术摘要：磁体中的磁矩可以形成各种称为自旋纹理的配置，例如磁畴壁，其中磁矩形成连接具有不同磁化方向的相邻磁域的缠绕配置。通常，自旋纹理中力矩的旋转方向预计是非手性的，其中左手和右手旋转同样可能。在某些磁性薄膜中，磁性层和重金属层之间的界面处原子结构的反演对称性被打破，导致界面效应，从而提高手性简并性并稳定手性自旋结构，例如自旋螺旋、手性畴壁或磁性斯格明子。这些手性自旋结构表现出优先的旋向性和迷人的拓扑特征。它们的非凡特性为磁性的基本问题提供了新的见解，并为新型磁性技术提供了令人兴奋的潜力。 该项目旨在通过解锁多个自由度以更好地理解和控制此类自旋纹理，从而显着推进该领域的发展。研究了几种新颖的自旋纹理，包括二维薄膜中奇异类型的斯格明子和手性畴壁以及拓扑自旋纹理，例如 3 维磁结构中的莫比乌斯带。它们有可能从根本上改变未来信息存储的能源格局。该项目为大学以及国家实验室和其他设施的学生提供了宝贵的培训机会。首席研究员积极致力于通过课程提供、公开讲座、交流访问和专业会议组织等方式扩大代表性不足群体的参与。技术摘要：对手性自旋纹理进行了研究，以展示一些新的自由度，以更好地提高代表性。控制它们，包括反斯格明子霍尔角、拓扑数、化学吸附物种和 3 维拓扑构型。利用各向异性 Dzyaloshinskii-Moriya 相互作用来稳定磁性薄膜中的反斯格明子。探索反斯格明子霍尔角用于控制斯格明子轨迹或拓扑排序，这可潜在用于设计复杂的斯格明子器件。演示了高绕数斯格明子，这将拓扑数解锁为新的自由度，可以支持逻辑器件中的新颖拓扑功能。研究了真空下化学吸附物质对铁磁体薄膜的影响，以诱导手性畴壁并能够在没有磁场或电场的情况下直接写入斯格明子。研究低原子序数原子和有机分子的化学吸附，以诱导磁手性的可逆切换和垂直磁各向异性的调节。制造了莫比乌斯带等新型 3 维拓扑自旋纹理，并研究了它们的拓扑特征。这些新颖的自旋纹理为稳健和低耗散的信息存储提供了新的机制，这与未来纳米电子学面临的巨大挑战非常契合。该项目包括为扩大代表性不足群体的参与而做出的各种努力。参与的学生将获得在学术界、政府实验室和其他研究机构的良好研究经验。这项 DMR 赠款支持在凝聚态物理 (CMP) 和电子和光子材料 (EPM) 项目的资助下对磁性纳米粒子中的手性自旋结构进行研究该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Machine-learning recognition of Dzyaloshinskii-Moriya interaction from magnetometry

通过磁力测量机器学习识别 Dzyaloshinskii-Moriya 相互作用

• DOI: 10.1103/physrevresearch.5.043012
• 发表时间: 2023-10
• 期刊: Physical Review Research
• 影响因子: 4.2
• 作者: Fugetta, Bradley J.;Chen, Zhijie;Bhattacharya, Dhritiman;Yue, Kun;Liu, Kai;Liu, Amy Y.;Yin, Gen
• 通讯作者: Yin, Gen

Room‐Temperature Magnetic Skyrmions and Large Topological Hall Effect in Chromium Telluride Engineered by Self‐Intercalation

自插层工程碲化铬中的室温磁斯格明子和大拓扑霍尔效应

• DOI: 10.1002/adma.202205967
• 发表时间: 2022-10-17
• 期刊: Advanced Materials
• 影响因子: 29.4
• 作者: Chen;Chen Liu;Junwei Zhang;Youyou Yuan;Y. Wen;Yan Li;D. Zheng;Qiang Zhang;Z. Hou;G. Yin;Kai Liu;Yong Peng;Xixiang Zhang
• 通讯作者: Xixiang Zhang

Observation of Hydrogen-Induced Dzyaloshinskii-Moriya Interaction and Reversible Switching of Magnetic Chirality

氢诱导的 Dzyaloshinskii-Moriya 相互作用和磁手性可逆转换的观察

• DOI: 10.1103/physrevx.11.021015
• 发表时间: 2021-04
• 期刊: Physical Review X
• 影响因子: 12.5
• 作者: Chen, Gong;Robertson, MacCallum;Hoffmann, Markus;Ophus, Colin;Fernandes Cauduro, André L.;Lo Conte, Roberto;Ding, Haifeng;Wiesendanger, Roland;Blügel, Stefan;Schmid, Andreas K.;et al
• 通讯作者: et al

Element-specific first order reversal curves measured by magnetic transmission x-ray microscopy

通过磁透射 X 射线显微镜测量的元素特定一阶反转曲线

• DOI: 10.1063/5.0122923
• 发表时间: 2022-10-11
• 期刊: APL Materials
• 影响因子: 6.1
• 作者: D. Gilbert;M. Im;Kai Liu;P. Fischer
• 通讯作者: P. Fischer

Magnetic Skyrmions with Unconventional Helicity Polarization in a Van Der Waals Ferromagnet

范德华铁磁体中具有非常规螺旋极化的磁性斯格明子

• DOI: 10.1002/adma.202204163
• 发表时间: 2022-09
• 期刊: Advanced Materials
• 影响因子: 29.4
• 作者: Zhang, Chenhui;Liu, Chen;Zhang, Senfu;Zhou, Bojian;Guan, Chaoshuai;Ma, Yinchang;Algaidi, Hanin;Zheng, Dongxing;Li, Yan;He, Xin;et al
• 通讯作者: et al