Studies of Quantum Magnetism with Magnetic Resonance and Thermodynamic Measurements

通过磁共振和热力学测量研究量子磁学

• 批准号: 436081-2013
• 负责人: Quilliam, Jeffrey
• 金额: $ 1.68万
• 依托单位: Université de Sherbrooke
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=633567
• 关键词: Studies; Quantum; Magnetism; Magnetic; Resonance

My group's research will primarily involve the study of magnetism in materials and will aim to expose and understand new quantum states of matter. Often this will be done by studying so-called frustrated magnets in which there is a competition between different energetic interactions so that they cannot all be simultaneously satisfied. The hope in such systems is to preclude ordinary magnetic order and obtain exotic ground states. For example, we will study frustrated materials called "spin ice" in which the basic excitations can be described as magnetic monopoles, as well as quantum spin liquid materials in which there may exist unusual quantum-entangled ground states. My group will also research materials known as multiferroics, which combine magnetism and electric polarization and may show some of the first applications for frustrated magnetism. Finally we will also study various conducting systems in which many degrees of freedom (including magnetism) and strong interactions between electrons lead to interesting quantum phases of matter. The primary research techniques that we will employ are solid-state nuclear magnetic resonance (NMR) and magnetic susceptibility measurements. Where susceptibility measurements reveal the sum of different magnetic contributions with high precision, NMR can separate out the different components and reveal the distribution of magnetic fields inside a sample. Thus this combined approach may be succinctly summarized as probing the magnetism both inside and outside of a sample. The unique combination of these two highly complementary techniques, over a very broad range of temperatures, from room temperature down to 20 mK above absolute zero, will position my research group to explore exciting quantum materials and make profound discoveries.

我们小组的研究将主要涉及材料磁性的研究，旨在揭示和理解物质的新量子态。这通常是通过研究所谓的受抑磁体来实现的，在这种磁体中，不同的能量相互作用之间存在竞争，因此它们不能同时满足。希望在这样的系统中排除普通的磁序，并获得奇异的基态。例如，我们将研究被称为“自旋冰”的受挫材料，其中基本激发可以被描述为磁单极子，以及量子自旋液体材料，其中可能存在不寻常的量子纠缠基态。我的小组还将研究被称为多铁性的材料，它结合了联合收割机的磁性和电极化，并可能展示一些挫折磁性的第一批应用。最后，我们还将研究各种传导系统，其中许多自由度（包括磁性）和电子之间的强相互作用导致物质的有趣量子相。我们将采用的主要研究技术是固态核磁共振（NMR）和磁化率测量。在磁化率测量以高精度揭示不同磁性贡献的总和的情况下，NMR可以分离出不同的组分并揭示样品内部的磁场分布。因此，这种组合方法可以简洁地概括为探测样品内部和外部的磁性。这两种高度互补的技术的独特组合，在非常广泛的温度范围内，从室温到绝对零度以上20 mK，将使我的研究小组能够探索令人兴奋的量子材料并取得深刻的发现。