Muon studies of quantum materials under extreme environments

在接下来的五年里，我的研究将集中在Muon自旋旋转/弛豫技术(µSR)在极端条件下的新型量子材料研究中的应用。我的目标是通过应用非热微扰(化学掺杂、磁场、压力)来将材料调整到量子临界，从而理解拓扑材料、非传统超导体和磁阻材料的显著物理性质，这些材料是由量子力学和强电子关联带来的。正Muon是一种在唯一微秒时间尺度上灵敏的内部磁场局部探测器，将在这项工作中被用来了解无序对量子材料奇异物理性质的影响。到目前为止，我已经在外加磁场和/或低温的极端环境中进行了量子材料的介子研究。我研究的一个新重点将是将GPA规模的高压能力整合到低温量子材料的介子研究中。高压可以用来使材料晶格中的原子更紧密地结合在一起，导致电子结构和磁相互作用的可调变化。这一目标将利用温哥华TRIUMF新的高动量和高亮度Muon束线的投资并及时完成和实施。新的研究基础设施将为加拿大和国际用户提供西半球无与伦比的能力，在正常和极端条件下研究量子系统。我和我的HQP将通过瑞士Paul Scherrer研究所(PSI)的量子材料合作实验，获得使用Muon进行高压研究的实际经验。目前，PSI是世界领先的用于量子材料研究的流体静压高压Muon设备的所在地。此外，在过去的一年里，一种由压电驱动的单轴压力室被完全开发出来，并成功地用于PSI的Muon实验。国外在这项研究中获得的知识对于在TRIUMF建立类似的高压研究能力将是非常宝贵的。我的团队还将获得执行材料中Muon停止位置的理论计算的知识和工具，以改进对我们实验数据的分析和解释。近年来，人们发展了可靠的计算介子位置的方法并将其应用于材料的介子研究。

Over the next five years my research will focus on the application of the muon spin rotation/relaxation technique (µSR) to studies of novel quantum materials under extreme conditions. My goal is to understand the remarkable physical properties of topological materials, unconventional superconductors, and magnetically frustrated materials, brought about by the effects of quantum mechanics and strong electronic correlations by applying non-thermal perturbations (chemical doping, magnetic field, pressure) to tune the material towards quantum criticality. The positive muon is a sensitive local probe of internal magnetic fields on a unique microsecond time scale and will be exploited in this work to understand the effects of disorder on the exotic physical properties of quantum materials. To date I have carried out muon studies of quantum materials in the extreme environments of applied magnetic field and/or low temperature. A new emphasis of my research will be the integration of high-pressure capabilities on the GPa scale into muon studies of quantum materials at low temperatures. High pressure can be used to bring atoms in the crystal lattice of a material closer together, inducing tunable changes of the electronic structure and magnetic interactions. This objective will exploit the investment and timely completion and implementation of new high momentum and high luminosity muon beam lines at TRIUMF, Vancouver. The new research infrastructure will provide Canadian and international users with unmatched capabilities in the Western Hemisphere to study quantum systems under normal and extreme conditions. My HQP and I will gain practical experience in high pressure research using muons via collaborative experiments on quantum materials at the Paul Scherrer Institute (PSI) in Switzerland. Currently, PSI is home to the world's leading hydrostatic high-pressure muon facility for quantum materials research. Moreover, this past year a piezoelectric-driven uniaxial pressure cell was fully developed and successfully utilized in a muon experiment at PSI. The knowledge gained in this research abroad will be invaluable for establishing an analogous high-pressure research capability at TRIUMF. My team will also gain the knowledge and tools for performing theoretical calculations of muon stopping sites in materials to improve the analysis and interpretation of our experimental data. In recent years, reliable methods for calculating muon sites have been developed and applied to muon studies of materials.