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，这主要是由于在即将到来的量子信息技术中应用的前景。磁体/超导混合(MSH)系统是设计具有可调谐性质的新型量子材料的很有前途的候选材料。在超导衬底和含有非共线自旋织构的超薄磁层之间的界面上，预计将出现丰富的新物理学。一方面，有报道称，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，预计在异质界面上将出现受拓扑保护的电子态和等自旋三重态，从而允许出现拓扑超导和自旋极化超导电流。在这里，我建议使用低温自旋极化低能电子显微镜(SPLEEM)来研究MSH量子系统。SPLEEM的独特能力将允许以纳米分辨率表征沉积的磁性薄膜和多层膜中的全三维自旋织构，作为温度(超导临界温度以下和之上)的函数，目的是了解超导对磁性层中稳定自旋织构的影响。通过利用加州劳伦斯伯克利国家实验室最近安装的低温SPLEEM的独特能力，所有这些都将成为可能。这是唯一在液态氦温度下运行的SPLEEM，并向外部用户开放。将对两种不同类型的MSH系统进行调查。最初，这项研究将集中在MSH系统上，在该系统中，块状超导体与磁性超薄膜和多层膜连接。该项目第一阶段的目标将是发现拥有非共线自旋织构的材料系统，以及温度如何影响它们的磁性基态。随后，我将研究更复杂的系统，在初始MSH系统的界面处插入一层薄薄的大自旋-轨道耦合材料。其目的是了解如何通过大的自旋-轨道耦合间层的存在来调节初始MSH系统的性质。