Exploring tunable magnet/superconductor hybrid quantum systems via spin-polarized low energy electron microscopy

通过自旋极化低能电子显微镜探索可调谐磁体/超导体混合量子系统

• 批准号: 512050965
• 负责人: Dr. Roberto Lo Conte, Ph.D.
• 金额: --
• 依托单位: Institut für Nanostruktur- und Festkörperphysik (INF)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2022
• 资助国家: 德国
• 起止时间: 2021-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/512050965?language=en
• 关键词: Exploring; tunable; magnet; superconductor; hybrid

In recent years the investigation of quantum materials has been experiencing an unprecedented acceleration, mostly due to the promise of applications in the upcoming quantum information technologies. Magnet/superconductor hybrid (MSH) systems are very promising candidates for designing new quantum materials with tunable properties. Rich new physics is expected to emerge at the interface between a superconducting substrate and an ultra-thin magnetic layer hosting non-collinear spin textures. On the one hand, it has been reported that the superconducting state of the substrate can control the magnetic phase established in the ultra-thin magnet. On the other hand, topologically protected electronic states and equal-spin triplets are predicted to be present at the hetero-interface due to the interplay between the non-collinear spin texture and the superconducting phase, allowing for the emergence of topological superconductivity and spin-polarized supercurrents.Here I propose to use low temperature spin-polarized low energy electron microscopy (SPLEEM) to investigate MSH quantum systems. The unique capabilities of SPLEEM will allow the characterization of the full 3-dimentional spin texture in the deposited magnetic thin films and multilayers with nanometer resolution as a function of temperature (below and above the superconducting critical temperature), with the aim of understanding the influence of superconductivity on the stabilized spin textures in the magnetic layers. All this will be possible by exploiting the unique capabilities of the recently installed low temperature SPLEEM at the Lawrence Berkeley National Laboratory in California, which is the only SPLEEM functioning at liquid He temperature and open for access to external users.Two different types of MSH systems will be investigated. Initially, the study will focus on MSH systems where a bulk superconductor is interfaced with magnetic ultra-thin films and multilayers. The goal of this initial phase of the project will be to discover materials systems hosting non-collinear spin textures and how temperature affects their magnetic ground state. Subsequently, I will study more complex systems, where a thin interlayer of a large spin-orbit coupling material will be inserted at the interface of the initial MSH system. The aim is to understand how the properties of the initial MSH system can be tuned by the presence of the large spin-orbit coupling interlayer.

近年来，量子材料的研究经历了前所未有的加速，主要是由于即将到来的量子信息技术的应用前景。磁体/超导体混合系统是设计具有可调性质的新型量子材料的一个非常有前途的候选者。丰富的新物理有望出现在超导衬底和超薄磁层之间的界面托管非共线自旋纹理。一方面，据报道，衬底的超导状态可以控制超薄磁体中建立的磁相。另一方面，由于非共线自旋织构和超导相之间的相互作用，拓扑保护的电子态和等自旋三重态被预测存在于异质界面处，从而允许拓扑超导性和自旋极化超电流的出现。SPLEEM的独特功能将允许以纳米分辨率表征沉积的磁性薄膜和多层中的完整三维自旋纹理，该分辨率是温度（低于和高于超导临界温度）的函数，目的是了解超导性的影响对磁性层中稳定的自旋纹理。所有这一切都将是可能的，利用最近安装的低温SPLEEM在加州的劳伦斯伯克利国家实验室，这是唯一的SPLEEM在液态He温度下运行，并开放给外部users.Two不同类型的MSH系统的独特功能将被调查。最初，该研究将集中在MSH系统中，大块超导体与磁性超薄膜和多层膜连接。该项目初始阶段的目标是发现具有非共线自旋纹理的材料系统以及温度如何影响其磁基态。随后，我将研究更复杂的系统，其中将在初始MSH系统的界面处插入大自旋轨道耦合材料的薄夹层。我们的目的是了解如何初始MSH系统的属性可以通过大的自旋轨道耦合夹层的存在下进行调谐。