Quantum dynamics of frustrated spin systems studied with high frequency susceptibility

用高频磁化率研究受挫自旋系统的量子动力学

• 批准号: 2268796
• 金额: --
• 依托单位: CARDIFF UNIVERSITY
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2268796
• 关键词: Quantum; dynamics; frustrated; spin; systems

We investigate the magnetic spin dynamics of bulk systems as quantum effects start to become relevant at low temperature. We do this by looking at spin relaxation using a variety of experimental probes. These range from neutrons and muons, where large particle accelerators are required to produce these particles which can then map out the fundamental properties, and laboratory based equipment. At Cardiff we have developed a high frequency susceptibility probe system which can operate from 50 mK to 400 K. Your PhD would focus on investigating frustrated materials with these techniques, specifically we look at materials where emergent phenomena occur, for example in the spin ice systems we have investigated the occurrence of magnetic monopoles. This is where excitations out of the frustrated ground state create magnetic excitations that undergo a Coulomb interaction, this novel result can be used to demonstrate that Maxwells equations have a direct symmetry between electrical and magnetic charges. In this project you will use a range of experimental techniques using dilution fridges and cryostats to probe the frequency response of the spin dynamics and then model the results based on the latest understanding in our field. You will join an existing group (2 PHD and a PDRA) and develop a range of skills covering experimental physics, modelling and project planning with opportunities to write papers and present work at international conferences. In the first 6 months of the project, training on the high frequency susceptometer, courses explaining theory of the field and use of central facilities will be given followed by 24 months of detailed research on single ion dynamics in spin ice at the quantum limit, and 12 months manuscript and thesis writing. The use of available, cutting edge equipment facilitated by dynamic weekly meetings will enable a fulfilling PhD.

当量子效应在低温下开始变得相关时，我们研究了大块系统的磁自旋动力学。我们通过使用各种实验探测器观察自旋弛豫来做到这一点。这些设备包括中子和µ子，这些粒子需要大型粒子加速器来产生这些粒子，然后这些粒子可以绘制出基本性质，以及基于实验室的设备。在加的夫，我们开发了一种高频磁化率探测系统，可以从50MK到400K运行。您的博士学位将专注于使用这些技术研究受挫材料，特别是我们研究发生紧急现象的材料，例如在自旋冰系统中，我们研究了磁单极子的发生。这就是受挫基态的激发产生的磁激发经历库仑相互作用的地方，这个新的结果可以用来证明麦克斯韦方程在电荷和磁电荷之间具有直接对称性。在本项目中，您将使用一系列使用稀释冰箱和低温恒温器的实验技术来探测自旋动力学的频率响应，然后根据我们领域的最新理解对结果进行建模。你将加入一个现有的小组(两个博士和一个PDRA)，并发展一系列技能，包括实验物理、建模和项目规划，并有机会撰写论文和在国际会议上发表工作。在该项目的前6个月，将提供高频磁化率计培训、解释场论和使用中央设施的课程，随后将提供24个月的详细研究量子极限自旋冰中的单离子动力学，以及12个月的手稿和论文写作。使用现有的尖端设备，通过动态的每周会议，将使一个令人满意的博士学位。