Synthesis and Advanced Characterization of Quantum Materials

量子材料的合成和高级表征

• 批准号: RGPIN-2014-05818
• 负责人: Luke, Graeme
• 金额: $ 3.5万
• 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: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=588636
• 关键词: Synthesis; Advanced; Characterization; Quantum; Materials

This proposal seeks support for my research program in the experimental study of Quantum Materials. These materials are important both for their future use in applications and because they are often not described by traditional theories. Such systems include high temperature superconductors including the newly discovered pnictides, low dimensional and geometrically frustrated magnets and materials with topological order. My research program is highly collaborative and interdisciplinary in nature, involving international leading scientists and both graduate and undergraduate students in all stages of the research. As a direct result of this research we will discover and characterize magnetic systems with a variety of exotic ground states including both quantum and classical quantum spin ices and liquids. We will identify possible broken time reversal symmetry superconducting states and perform detailed studies of the fundamental properties of newly discovered superconductors. Magnetic systems to be studied include pyrochlore iridates which combine strong spin-orbit coupling and topological order with geometrical frustration. We will synthesize other pyrochlores such as Tb2GeO7, Yb2GeO7, Ho2Ge2O7, Pr2Pb2O7 and Nd2Pb2O7 then perform muon spin relaxation, neutron scattering, magnetization and other studies using both in-house and international user facilities to identify a variety of novel magnetic ground states. We will synthesize other systems with geometrical frustration including the spinels BaHo2O4 and FeV2O4, searching for exotic ground states and novel emergent spin excitations. We will perform detailed muon spin relaxation/rotation studies of the doped topological insulator CuxBi2Se3 and other potential topological superconductors to search for evidence of a topological superconducting state. We will continue our study of Sr2RuO4 which has been identified as a chiral p-wave topological superconductor, using ß-NMR to search for characteristic edge currents near the sample surface. We will continue our efforts to fully understand the electronic and magnetic states of URu2Si2. We will use chemical substitutions to drive the system to a quantum critical point, using muons and neutrons with bulk techniques to study this evolution. My research program is at an exciting juncture with new experimental facilities coming online at present in the imminent future. These include new muon beamlines at TRIUMF with enhanced capabilities, greatly increased beamtime for ß-NMR due to the development of an additional driver accelerator and the development of a very low temperature (T<0.5K) spectrometer for ß-NMR. A new SQUID magnetometer with 3He capability (T<0.5K) will be installed in my laboratory during late 2013. The proposed studies will involve a wide range of experimental techniques, starting with materials synthesis using optical image and tri-arc furnaces. We will measure magnetic susceptibility down to 0.5K using our new low temperature SQUID magnetometer (a unique capability in Canada). We will perturb systems using extreme conditions of high magnetic field and hydrostatic pressure. We will use both conventional and low energy muon spin relaxation/rotation and ß-NMR to measure the local real space magnetic behavior in both bulk and thin film specimens. Finally, my students and I will collaborate with leading groups for studies using a variety of experimental techniques including scanning tunneling microscopy, neutron scattering and angle-resolved photoemission spectroscopy.

该提案寻求对我在量子材料实验研究中的研究计划的支持，这些材料对于它们未来的应用非常重要，因为它们通常没有被传统理论描述，包括新发现的磷族元素。具有拓扑顺序的低维和几何挫败磁体和材料。 我的研究项目本质上是高度协作和跨学科的，国际领先的科学家以及研究生和本科生参与了研究的各个阶段，作为这项研究的直接结果，我们将发现并表征具有各种奇异基态的磁系统，包括两者。我们将识别可能的破缺时间反转对称超导态，并对新发现的超导体的基本特性进行详细研究。 要研究的磁系统包括烧绿石铱酸盐，它结合了强自旋轨道耦合和拓扑序与几何挫败性。我们将合成其他烧绿石，例如Tb2GeO7、Yb2GeO7、Ho2Ge2O7、Pr2Pb2O7和Nd2Pb2O7，然后进行μ子自旋弛豫、中子散射、磁化等。使用内部和国际用户设施进行研究，以确定各种新颖的我们将合成具有几何挫败性的其他系统，包括尖晶石 BaHo2O4 和 FeV2O4，寻找奇异的基态和新颖的自旋激发。 我们将对掺杂拓扑绝缘体 CuxBi2Se3 和其他潜在拓扑超导体进行详细的 μ 子自旋弛豫/旋转研究，以寻找拓扑超导态的证据。我们将继续对已被确定为手性 p 波拓扑超导体的 Sr2RuO4 进行研究。 ，使用 ß-NMR 搜索样品表面附近的特征边缘电流。 我们将继续努力，充分了解 URu2Si2 的电子和磁态。我们将使用化学替代将系统驱动到量子临界点，并使用 μ 子和中子以及体技术来研究这种演化。 我的研究计划正处于一个激动人心的时刻，新的实验设施即将在不久的将来上线，其中包括 TRIUMF 的新 μ 子束线，其功能增强，由于开发了额外的驱动加速器和 β-NMR 的束时间大大增加。开发用于 ß-NMR 的极低温 (T<0.5K) 光谱仪 后期将在我的实验室安装具有 3He 功能 (T<0.5K) 的新型 SQUID 磁力计。 2013年。 拟议的研究将涉及广泛的实验技术，从使用光学图像和三弧炉的材料合成开始，我们将使用我们的新型低温 SQUID 磁力计（加拿大独有的功能）测量低至 0.5K 的磁化率。将使用高磁场和静水压的极端条件扰动系统，我们将使用传统和低能μ子自旋弛豫/旋转和β-NMR来测量体膜和薄膜中的局部真实空间磁行为。最后，我和我的学生将与领导小组合作，使用各种实验技术进行研究，包括扫描隧道显微镜、中子散射和角分辨光电子能谱。