Controlling Magnetism, Metal-Insulator Transitions, and Superconductivity in Ruthenate Thin Films

控制钌酸盐薄膜中的磁性、金属-绝缘体转变和超导性

• 批准号: 1709255
• 负责人: Kyle Shen
• 金额: $ 42.5万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-15 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1709255&HistoricalAwards=false
• 关键词: Controlling; Magnetism; Metal; Insulator; Transitions

Non-Technical Abstract: The electronic and magnetic properties of materials form the backbone of modern technologies, including computer processors, telecommunications, information storage, and displays. Moreover, the ability to deterministically control these properties, for instance, in semiconductor transistors, is one of the crowning achievements of materials physics in the past fifty years and has had enormous societal and economic impacts. However, the end of Moore's Law and the increasing need for smaller, faster, and more power efficient electronics demands the search for new electronic materials that can ultimately replace existing materials such as silicon and copper which have been in use for nearly half a century. This project aims to investigate one class of electronic materials comprised of ruthenium oxides which exhibit a tremendous variety of electronic and magnetic properties, some of which could be potentially important for a wide range of applications including quantum computing, non-volatile memories, and sensing. These materials are synthesized as thin films which are only a few atoms thick, and their properties are manipulated by controlling the thickness of the film or stretching the bonds between atoms. Advanced spectroscopic tools allow for a more detailed understanding of how to better optimize and control their desired properties. Finally, this project provides crucial training to young scientists in materials synthesis and characterization, and the samples fabricated in these studies support a number of scientific collaborations both nationwide and internationally.Technical Abstract: A major challenge in condensed matter physics is to control the many-body interactions in correlated quantum materials with the objective of being able to engineer their properties in a deterministic fashion. The potential for quantum materials as platforms for future technologies such as topological quantum computation or memories has motivated an effort to discover new avenues to measure and manipulate their electronic and magnetic structure. The strategy outlined in this proposal is to use the family of layered ruthenates which exhibit a range of emergent electronic and magnetic phenomena, including spin-triplet superconductivity, electronic nematicity, quantum criticality, and metal-insulator transitions, as a platform for manipulating electronic and magnetic properties through epitaxial strain, particularly since the properties of ruthenates are particularly responsive to small perturbations. This project combines oxide molecular beam epitaxy growth and in situ high-resolution angle-resolved photoemission to investigate the electronic structure of the ruthenates, and how the band structure and Fermi surfaces responds to strain. Graduate students involved in this project are trained in molecular beam epitaxy growth, photoemission spectroscopy, and a multitude of sample characterization techniques. Some specific objectives of this work include increasing the superconducting Tc of Sr2RuO4 via epitaxial strain, and gaining insight into the mechanism of spin-triplet superconductivity by correlating Tc with changes in the Fermi surface topology. Another goal is to control the magnetic field driven quantum phase transition in Sr3Ru2O7 by changing the RuO6 octahedral rotation angles through epitaxial strain, and correlating these behaviors with changes in the electronic structure.

非技术摘要：材料的电子和磁性特性构成了现代技术的支柱，包括计算机处理器、电信、信息存储和显示。此外，确定性地控制这些特性的能力（例如在半导体晶体管中）是过去五十年材料物理学的最高成就之一，并且产生了巨大的社会和经济影响。然而，摩尔定律的终结以及对更小、更快、更节能的电子产品日益增长的需求要求寻找新的电子材料，以最终取代已经使用了近半个世纪的现有材料，如硅和铜。该项目旨在研究一类由氧化钌组成的电子材料，这些材料具有多种电子和磁性特性，其中一些特性可能对包括量子计算、非易失性存储器和传感在内的广泛应用具有潜在的重要意义。这些材料被合成为只有几个原子厚的薄膜，它们的性能可以通过控制薄膜的厚度或拉伸原子之间的键来控制。先进的光谱工具可以更详细地了解如何更好地优化和控制其所需的特性。最后，该项目为年轻科学家提供了材料合成和表征方面的重要培训，这些研究中制造的样品支持了国内外的许多科学合作。 技术摘要：凝聚态物理的一个主要挑战是控制许多-相关量子材料中的物体相互作用，目的是能够以确定性的方式设计它们的特性。量子材料作为拓扑量子计算或存储器等未来技术平台的潜力促使人们努力发现测量和操纵其电子和磁性结构的新途径。该提案中概述的策略是使用层状钌酸盐家族，这些钌酸盐家族表现出一系列新兴的电子和磁性现象，包括自旋三重态超导性、电子向列性、量子临界性和金属-绝缘体跃迁，作为操纵电子和磁性现象的平台。通过外延应变来改变磁性，特别是因为钌酸盐的特性对小扰动特别敏感。该项目结合了氧化物分子束外延生长和原位高分辨率角分辨光电发射来研究钌酸盐的电子结构，以及能带结构和费米表面如何响应应变。参与该项目的研究生接受了分子束外延生长、光电子能谱和多种样品表征技术的培训。这项工作的一些具体目标包括通过外延应变提高 Sr2RuO4 的超导 Tc，并通过将 Tc 与费米表面拓扑的变化相关联来深入了解自旋三重态超导机制。另一个目标是通过外延应变改变 RuO6 八面体旋转角度，并将这些行为与电子结构的变化相关联，从而控制 Sr3Ru2O7 中磁场驱动的量子相变。

项目成果

Revealing the hidden heavy Fermi liquid in CaRuO3

揭示 CaRuO3 中隐藏的重费米液体

• DOI: 10.1103/physrevb.98.041110
• 发表时间: 2018-07
• 期刊: PHYSICAL REVIEW B
• 影响因子: 3.7
• 作者: Liu Yang;Nair Hari P.;Ruf Jacob P.;Schlom Darrell G.;Shen Kyle M.
• 通讯作者: Shen Kyle M.

Quantum oscillations and quasiparticle properties of thin film Sr2RuO4

• DOI: 10.1103/physrevb.104.045152
• 发表时间: 2021-03
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Yawen Fang;H. Nair;L. Miao;B. Goodge;N. Schreiber;J. Ruf;L. Kourkoutis;K. Shen;D. Schlom;B. Ramshaw

Two-dimensional magnetic monopole gas in an oxide heterostructure

• DOI: 10.1038/s41467-020-15213-z
• 发表时间: 2020-03-12
• 期刊: NATURE COMMUNICATIONS
• 影响因子: 16.6
• 作者: Miao, L.;Lee, Y.;Shen, K. M.
• 通讯作者: Shen, K. M.

Strain relaxation induced transverse resistivity anomalies in SrRuO3 thin films

• DOI: 10.1103/physrevb.102.064406
• 发表时间: 2020-08
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: L. Miao;N. Schreiber;H. Nair;B. Goodge;Shengwei Jiang;J. Ruf;Yonghun Lee;Matthew Fu;B. Tsang;Yingfei Li;C. Zeledon;J. Shan;K. Mak;L. Kourkoutis;D. Schlom;K. Shen

Subterahertz Momentum Drag and Violation of Matthiessen’s Rule in an Ultraclean Ferromagnetic SrRuO3 Metallic Thin Film

超净铁磁 SrRuO3 金属薄膜中的亚太赫兹动量阻力和违反马蒂森规则

• DOI: 10.1103/physrevlett.125.217401
• 发表时间: 2020
• 期刊: Physical Review Letters
• 影响因子: 8.6
• 作者: Wang, Youcheng;Bossé, G.;Nair, H. P.;Schreiber, N. J.;Ruf, J. P.;Cheng, B.;Adamo, C.;Shai, D. E.;Lubashevsky, Y.;Schlom, D. G.
• 通讯作者: Schlom, D. G.