Microscopic investigation of quantum materials based on nuclear magnetic resonance

基于核磁共振的量子材料微观研究

• 批准号: RGPIN-2018-06365
• 负责人: imai, takashi
• 金额: $ 3.72万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=654240
• 关键词: Microscopic; investigation; quantum; materials; based

The scientific goal of our fundamental research is to understand the non-intuitive behavior of solids driven by quantum mechanics. Two major pillars of our intellectual pursuit are quantum magnetism and exotic superconductivity. The former examines magnetic moments in frustrated “spin liquids” that continue fluctuating near absolute zero without undergoing a phase transition. In essence, these magnets behave as if they were not a magnet. Deciphering their mysterious properties is the holy grail of today's quantum materials research. The latter seeks understanding of the mechanisms behind sudden disappearance of electrical resistance in some classes of copper-oxides and iron-pnictides. ******NSERC Discovery Grant enables us to investigate these fundamental problems of physics based on a microscopic probe called Nuclear Magnetic Resonance (NMR) spectroscopy. NMR is the underlying principle behind the magnetic resonance imaging (MRI) used in hospitals. NMR is exceptional at gaining deep insight at microscopic levels into why electrons and atoms behave the way they do. We investigate quantum materials using NMR conducted in extreme environments, such as low temperatures near absolute zero, ultra high pressure, and/or high magnetic field. ******My students conduct in-house research in our phenomenally well-equipped cryogenic NMR laboratory. They have unlimited access to three sets of NMR spectrometers, three types of superconducting magnets which can generate high magnetic fields up to 16 Tesla, high pressure cells to reach 3 to 9 GPa, and top-loading helium-3 and dilution refrigerators with the base temperature as low as 0.35 K and 0.009 K, respectively. The total value of these infrastructure exceeds $2-million. Their operational cost is very high, but so are the rewards to my students and Canada. Our superb research capabilities allow my students to establish high caliber collaborations with the world's leading researchers and publish high profile papers. The broad array of equipment also helps my students develop problem solving skills through hands-on training on the electronics, designing, manufacturing, installation and maintenance of cryogenic gears, and computer interfacing of sophisticated electronics. The versatile nature of my student training at all levels from undergraduate to postdoctoral researchers leads to a wide variety of career opportunities for them. ******In the coming 5 years, I propose to extend our research operation both in terms of the group size and scope. We are venturing into a new exciting direction of research on frustrated magnetism in the pyrochlore lattice, while maintaining our strength in research on kagome spin liquids. We also plan to refocus our attention on investigations of copper- and iron-based high temperature superconductors in view of the recent developments in the research field.

我们基础研究的科学目标是理解由量子力学驱动的固体的非直观行为。我们智力追求的两大支柱是量子磁性和奇异的超导电性。前者研究受挫的“自旋液体”中的磁矩，这些液体在绝对零度附近继续波动，而不经历相变。从本质上讲，这些磁铁的行为就像它们不是磁铁一样。破译它们的神秘性质是当今量子材料研究的圣杯。后者试图了解某些类型的铜氧化物和铁氧化物中电阻突然消失的机制。*NSERC Discovery Grant使我们能够基于一种名为核磁共振(核磁共振)光谱的微观探测器来研究这些基本的物理问题。核磁共振是医院使用的磁共振成像(MRI)背后的基本原理。核磁共振在微观层面上获得了对电子和原子行为方式的深入洞察，这方面是不同寻常的。我们使用在极端环境下进行的核磁共振来研究量子材料，例如绝对零度附近的低温、超高压和/或强磁场。*我的学生在我们设备精良的低温核磁共振实验室进行内部研究。他们可以无限使用三套核磁共振谱仪，三种可产生高达16特斯拉磁场的超导磁体，高达3至9 Gpa的高压室，以及分别低至0.35K和0.009 K的顶装式氦-3和稀释冰箱。这些基础设施的总价值超过200万美元。他们的运营成本非常高，但对我的学生和加拿大的回报也是如此。我们高超的研究能力使我的学生能够与世界领先的研究人员建立高水平的合作关系，并发表备受瞩目的论文。种类繁多的设备还帮助我的学生通过电子、低温齿轮的设计、制造、安装和维护以及尖端电子设备的计算机接口等方面的实践培训，培养解决问题的技能。从本科生到博士后研究人员，我的学生在所有级别的培训都是多才多艺的，这为他们带来了各种各样的职业机会。*在未来5年，我建议扩大我们的研究行动，无论是从团队规模还是范围。我们正在冒险进入一个新的令人兴奋的方向，研究焦绿石晶格中的受挫磁性，同时保持我们在Kagome自旋液体研究方面的实力。鉴于铜基和铁基高温超导体研究领域的最新发展，我们还计划将注意力重新集中在该领域的研究上。