International network to explore novel superconductivity at advanced oxide superconductor/magnet interfaces and in nanodevices

国际网络探索先进氧化物超导体/磁体界面和纳米器件的新型超导性

• 批准号: EP/P026311/1
• 负责人: Jason Robinson
• 金额: $ 87.22万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FP026311%2F1
• 关键词: International; network; explore; novel; superconductivity

This International Network of world-leading experimental and theoretical groups in Japan, South Korea, Italy and the UK will lead a programme to explore novel superconductivity at oxide superconductor interfaces with magnetic materials and in nanodevices. Through a better understanding of materials properties and processing, our vision is to realise full control over superconducting symmetry at oxide interfaces and to setup Cambridge and Kyoto as a global hubs to explore the science of advanced oxide interfaces and unconventional superconductivity. The past decade has seen rapid developments in the understanding of unconventional superconductivity at the interface between conventional (s-wave) superconductors and ferromagnets [Nature Physics 11, 307 (2015)]. A highlight was the experimental demonstration of a triplet proximity effect by the UK applicants [Science 329, 59 (2010)], which required the transformation of spin-singlet Cooper pairs by a spin-mixing interface into spin-triplet pairs. Another example is a possible creation of electron-composite particle-antiparticles in nanowire/superconductor devices. Such Majorana Fermions are also expected in a half-quantum flux state of a spin-triplet superconductor, and the Japanese core member (Maeno) obtained the first evidence for this using superconducting micro-rings [Science 311, 186 (2011)]. In parallel, the understanding of unconventional superconductivity in superfluid helium and in compounds such as Sr2RuO4 (SRO) [e.g. Science 331, 186-188 (2011) and Science 344, 283 (2014)] has also seen dramatic advances. The triplet (p-wave) state in SRO is even-frequency and is conceptually different to the odd-frequency triplet pairing induced in ferromagnets on s-wave superconductors. However, there are theoretical predictions that alternative pairing states can be induced at surfaces, which raise the prospect of coupling different superconducting states via interface-engineered proximity effects between SRO and conventional superconductors. One of the key aims of the Network is to investigate the coupling of different superconducting symmetries taking SRO and ferromagnet/superconductor structures as a model system. There are theoretical predictions that the surface of SRO and ferromagnet/superconductor hybrids can support an induced odd-frequency triplet-state and so there should be a proximity effect from the conventional superconductor which would create or enhance the superconductivity in a SRO crystal or thin-film. Achieving this will enable detailed studies of the electron pairing state in SRO and the mixing of different superconducting order parameters, which have not previously been possible with single crystal samples.To bridge these novel superconducting states at oxide interfaces, further materials developments are critical. The global interest in unconventional superconductivity and recent high-impact realisations could lead to transformative science and simultaneously offer new paradigms of cryogenic computing and encryption. To lead this research, the Cambridge and Kyoto hubs will bring together different specialities including superconductivity, thin-film and crystal growth of oxides, materials characterization (XMCD, low energy muon spectroscopy, pump-probe terahertz spectroscopy, angle-resolved photoemission, electron microscopy), nanofabrication and theory. The members of the Network will work closely together with PhD students, PDRAs and investigators undertaking routine research visits between the member groups. As importantly the Network will actively engage with the wider scientific community through the organisation of conferences and student workshops, and research visits with the overarching aim of triggering a long-term global effort to lift basic science to application.

这个在日本，韩国，意大利和英国的世界领先实验和理论团体的国际网络将领导一项计划，以探索具有磁性材料和纳米电视的氧化物超导体接口的新型超导性。通过更好地理解材料的性能和处理，我们的视野是实现对氧化物界面上超导对称性的完全控制，并将剑桥和京都设置为全球枢纽，以探索高级氧化物界面和非常常规的超导性的科学。在过去的十年中，在传统（S-WAVE）超导体和铁磁体之间的界面上对非常规超导性的理解方面有了迅速发展[自然物理学11，307（2015）]。一个亮点是英国申请人对三胞胎接近效应的实验证明[Science 329，59（2010）]，它需要通过旋转粘合界面转换为自旋 - 单词库珀对转换为旋转三曲线对。另一个例子是在纳米线/超导体设备中可能创建电子复合粒子抗粒子。预计在自旋三旋转超导体的半量子通量状态下，这种主要的费米也有望，而日本核心成员（Maeno）使用超导微型微环获得了第一个证据[Science 311，186（2011）]。同时，对超流体氦气和SR2RUO4（SRO）等化合物中非常规超导的理解[例如科学331，186-188（2011）和科学344，283（2014）]也看到了巨大的进步。 SRO中的三重态（P波）状态甚至是频率的，并且在概念上与S波超导体的Ferromagnets诱导的奇数频率三联成配对不同。但是，有理论上的预测可以在表面上诱导替代配对状态，从而通过SRO和常规超导体之间的界面工程接近效应来提高不同超导状态的前景。网络的关键目的之一是研究以SRO和Ferromagnet/超导体结构为模型系统的不同超导对称性的耦合。有理论上的预测，SRO和Ferromagnet/超导体杂种的表面可以支持诱导的奇数频率三重态，因此应该从传统的超导体产生邻近效应，从而在Sro Crystal或Fillm中产生或增强超导性。实现这一目标将使对SRO中的电子配对状态以及不同超导顺序参数的混合进行详细研究，而单个晶体样品以前尚不可能发生，桥接这些新型超导状态在氧化物界面上，进一步的材料开发至关重要。全球对非常规超导性和最近的高影响力实现的兴趣可能导致变革性的科学，并同时提供低温计算和加密的新范式。为了领导这项研究，剑桥和京都枢纽将汇集不同的特殊特殊性，包括超导性，薄膜和氧化物的晶体生长，材料表征（XMCD，低能雄性光谱，泵浦 - 泵 - 螺旋形terahertz光谱镜检查，角度分辨的光学显微镜，电子显微镜，Nananofabrication和Theopition。该网络的成员将与博士生，PDRA和调查人员紧密合作，进行成员群体之间的常规研究访问。重要的是，网络将通过组织和学生研讨会的组织积极与更广泛的科学界互动，并以触发全球长期努力来提高基础科学的长期努力的总体目的进行研究访问。

项目成果

A Review of Electronic Transport in Superconducting Sr2RuO4 Junctions

• DOI: 10.3390/coatings11091110
• 发表时间: 2021-09
• 期刊: Coatings
• 影响因子: 3.4
• 作者: M. Anwar;J. Robinson

A Review of Electronic Transport in Superconducting Sr$_2$RuO$_4$ Junctions

超导 Sr$_2$RuO$_4$ 结中电子输运综述

• DOI: 10.48550/arxiv.2109.05851
• 发表时间: 2021
• 作者: Anwar M

Colloquium: Spin-orbit effects in superconducting hybrid structures

研讨会：超导混合结构中的自旋轨道效应

• DOI: 10.48550/arxiv.2210.03549
• 发表时间: 2022
• 作者: Amundsen M

Anomalous anisotropic behaviour of spin-triplet proximity effect in Au/SrRuO3/Sr2RuO4 junctions

Au/SrRuO3/Sr2RuO4 结中自旋三重态邻近效应的反常各向异性行为

• DOI: 10.1038/s41598-019-52003-0
• 发表时间: 2019
• 期刊: Scientific Reports
• 影响因子: 4.6
• 作者: Anwar M

Anomalous anisotropic behaviour of spin-triplet proximity effect in Au/SrRuO3/Sr2RuO4 junctions.

Au/SrRuO3/Sr2RuO4 结中自旋三重态邻近效应的异常各向异性行为。

• DOI: 10.17863/cam.44832
• 发表时间: 2019
• 作者: Anwar M