Antiferromagnetic spin transport - from Hematite to Orthoferrites

反铁磁自旋输运 - 从赤铁矿到正铁氧体

• 批准号: 423441604
• 负责人: Professor Dr. Mathias Kläui
• 金额: --
• 依托单位: Arbeitsgruppe Theorie magnetischer Materialien
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/423441604?language=en
• 关键词: Antiferromagnetic; spin; transport; Hematite; Orthoferrites

Spintronics is a field of research that focuses on the transport and control of angular momentum in typically nano-structured materials. For the transport of angular momentum, traditionally spin-polarized electrons have been used as the carrier in metals. More recently, the focus has shifted to using magnonic spin currents, which can exist in low damping magnetic insulators without ohmic losses. For this burgeoning field of insulator spintronics conventionally ferrimagnetic insulators have been developed and only recently antiferromagnets were demonstrated to exhibit favourable properties as active components, since essential functionalities of antiferromagnets - electrical reading and writing - have been demonstrated. Antiferromagnetic insulators, specifically, have recently gained attention due to their low loss spin transport and ultra-fast dynamics boding well for use in next-generation spintronic devices. Hematite, the main constituent of rust, is a type of insulating antiferromagnetic mineral, which is a promising candidate in this context due to its ability to transport spin information over long distances, which has been in the focus of our preceding joint project. Within this follow-up proposal, we want to exploit the ability of Hematite to be doped to flexibly tune its magnetic and transport properties and study in particular the impact of the anisotropy on the spin transport. Beyond hematite, we extend our study to a promising class of dielectric antiferromagnets, which is rare-earth orthoferrites. While related to Hematite in terms of their magnetic properties, these materials can exhibit a wide range of strongly anisotropic properties leading to spin reorientation transitions, weak ferromagnetism, as well as tunable damping. This project will synergetically combine experimental and theoretical approaches to investigate and understand the mechanisms of magnonic spin transport in selectively doped hematite and particular orthoferrites. The necessary sample growth of thin hematite and orthoferrite films will be developed and optimized, while at the same time parameterizing spin models on the basis of ab initio calculations. The magnetostatic and dynamic properties are then investigated by a combination of magneto-transport measurements, magnetic imaging and multiscale simulations. The main goal is the understanding of the effects of the composition and doping on the magnetic transport. Furthermore, the project will probe the transport of angular momentum by hybrid quasiparticles, such as magnon-phonon polarons. Having understood the transport properties, we will finally explore the potential of these materials for use in novel device concepts by controlling lateral transport using local gating and vertical transport across a magnon spin valve. In conclusion, this project will underpin very promising current research efforts to exploit the advantages of antiferromagnetic insulators for the development of new spintronic devices.

自旋电子学是一个研究领域，专注于典型纳米结构材料中角动量的传输和控制。对于角动量的传输，传统上自旋极化电子被用作金属中的载流子。最近，焦点已经转移到使用磁振子自旋电流，其可以存在于低阻尼磁性绝缘体中而没有欧姆损耗。对于这个新兴的绝缘体自旋电子学领域，传统上已经开发了亚铁磁绝缘体，并且直到最近才证明反铁磁体作为活性组分表现出有利的性质，因为反铁磁体的基本功能-电阅读和写入-已经被证明。特别是反铁磁绝缘体，由于其低损耗的自旋输运和超快的动力学特性，最近受到了人们的关注，这预示着它将用于下一代自旋电子器件。铁锈的主要成分赤铁矿是一种绝缘反铁磁矿物，由于其能够长距离传输自旋信息，因此在这方面是一种很有前途的候选矿物，这一直是我们先前联合项目的重点。在这一后续提案中，我们希望利用赤铁矿的掺杂能力，灵活地调整其磁性和输运性质，特别是研究各向异性对自旋输运的影响。除了赤铁矿，我们将我们的研究扩展到一类有前途的介电反铁磁体，这是稀土正铁氧体。虽然在磁性方面与赤铁矿相关，但这些材料可以表现出广泛的强各向异性特性，导致自旋重取向转变，弱铁磁性以及可调阻尼。本计画将以联合收割机结合实验与理论的方法，研究与了解选择性掺杂赤铁矿与特定正铁酸盐中磁振子自旋输运的机制。必要的样品生长薄的赤铁矿和orthoterite薄膜将开发和优化，而在同一时间参数化自旋模型从头计算的基础上。静磁和动态性能的磁输运测量，磁成像和多尺度模拟相结合的研究。主要目标是了解组成和掺杂对磁输运的影响。此外，该项目将探测混合准粒子（如磁振子-声子极化子）的角动量输运。在了解了输运特性后，我们最终将通过使用局部门控控制横向输运和跨磁振子自旋阀的垂直输运来探索这些材料在新型器件概念中使用的潜力。总之，这个项目将支持非常有前途的当前研究工作，利用反铁磁绝缘体的优势，开发新的自旋电子器件。