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: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=611862
• 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.

该建议在量子材料实验研究中寻求我的研究计划的支持。这些材料对于它们在应用中的未来使用都很重要，并且因为它们通常不会由传统理论描述。这样的系统包括高温超导体，包括新发现的青霉素，低维和几何沮丧的磁铁以及具有拓扑顺序的材料。 我的研究计划本质上是高度协作和跨学科的，在研究的各个阶段都涉及国际领先的科学家以及研究生和本科生。作为这项研究的直接结果，我们将发现并表征具有各种外来基态在内的磁系统，包括量子和经典的量子旋转和液体。我们将确定可能破裂的时间逆转对称性超导状态，并对新发现的超导体的基本特性进行了详细的研究。 研究磁系统包括pyrochlore的虹膜液，将强的自旋轨道耦合和拓扑顺序与几何挫败感结合在一起。我们将综合其他pyrochlores，例如TB2GEO7，YB2GEO7，HO2GE2O7，PR2PB2O7和ND2PB2O7，然后进行MUON自旋松弛，中子散射，磁化和其他研究，并使用内部和国际用户都确定各种新型磁性地面状态。我们将综合其他具有几何挫败感的系统，包括刺Baho2O4和FeV2O4，寻找异国情调的基础状态和新颖的新兴旋转激发。 我们将对掺杂的拓扑绝缘子CUXBI2SE3和其他潜在的拓扑超导体进行详细的MUON自旋松弛/旋转研究，以寻找拓扑超导体的证据。我们将继续对SR2RUO4进行研究，该SR2RUO4已被确定为手性P-波拓扑超导体，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的电子和磁状态。我们将使用化学替代品将系统驱动到量子临界点，并使用带有大量技术的中子和中子来研究这种演变。 我的研究计划正处于一个令人兴奋的关头，目前在即将来临的未来，新的实验设施在线上。其中包括具有增强功能的TriumF的新型MUON梁线，由于开发了额外的驱动器加速器，并且开发了非常低的温度（t <0.5K）ß-NMR，因此β-NMR的光束时间大大增加了。 2013年底，我的实验室将安装具有3HE功能（T <0.5K）的新型鱿鱼磁力计（T <0.5K）。 拟议的研究将涉及多种实验技术，从使用光学图像和Tri-Arc熔炉材料合成开始。我们将使用新的低温鱿鱼磁力计（加拿大独特的能力）测量磁化率降至0.5K。我们将使用高磁场和静水压力的极端条件扰动系统。我们将同时使用常规和低能量的旋转弛豫/旋转和β-NMR来测量散装和薄膜标本中的局部真实空间磁性行为。最后，我和我的学生将使用各种实验技术与领先的小组合作进行研究，包括扫描隧道显微镜，中子散射和角度分辨光发射光谱。