Materials World Network: Quantum Dynamics and Onset of Magnetic Correlations in Single-Ion Magnets

材料世界网络：单离子磁体中的量子动力学和磁相关性的开始

• 批准号: 0710525
• 负责人: Michael Graf
• 金额: $ 30.9万
• 依托单位: Boston College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0710525&HistoricalAwards=false
• 关键词: Materials; World; Network; Quantum; Dynamics

The magnetic rare-earth ions (for example, triply ionized holmium) introduced at small concentrations into single crystal Lithium Yttrium Fluoride, form a class of nanoscale materials called single-ion magnets. These systems are relatively new and exhibit a fascinating variety of magnetic phenomena associated with the coupled electro-nuclear states of the holmium ion. Not only are these systems scientifically interesting, but they possess important technological relevance for the development of q-bits for quantum computers and for the development of dense magnetic recording media. This project uses Nuclear Magnetic Resonance (NMR), muon spin resonance and AC thermal measurements to study these nanomagnets. The results from these experiments will be used to understand the spin dynamics and decoherence in this system via interactions with the surrounding atoms and to characterize the onset of magnetic correlations as a function of increasing dipolar coupling strength, which is changed by varying holmium ion concentration. Studies on a related interesting hybrid single-ion molecular magnet terbium di-pthalocyanine, will also be carried out.This project is a collaborative effort involving research groups at the University of Pavia, Italy, the Louis Néel Laboratory in Grenoble, France, and Boston College. In addition, the muon user facilities at ISIS - Rutherford Appleton Laboratory (UK), and the Paul Scherrer Institute (Switzerland) will be used to carry out parts of the proposed research. Additional scientific support for the project through sample fabrication and theoretical analysis involves colleagues at the Vavilov Optical Institute and Kazan State University in Russia, respectively. Thus the proposed work will provide US graduate and undergraduate students with exceptional educational opportunities through extended research visits to some of the above laboratories and by participation in formal training workshops for NMR and muon spectroscopy at European facilities. Furthermore, the US junior researchers will gain valuable experience in the field of molecular magnetism, and become familiar with techniques of muon spin spectroscopy, areas in which the US is currently under-represented.This award is co-supported by the Division of Materials Research and the Office of International Science and Engineering.

将低浓度的磁性稀土离子（例如三电离钬）引入单晶氟化钇锂中，形成一类称为单离子磁体的纳米级材料。这些系统相对较新，并表现出与钬离子的电核耦合态相关的各种令人着迷的磁现象。 这些系统不仅在科学上很有趣，而且对于量子计算机的 q 位的开发和密集磁记录介质的开发具有重要的技术相关性。该项目使用核磁共振 (NMR)、μ子自旋共振和交流热测量来研究这些纳米磁体。 这些实验的结果将用于通过与周围原子的相互作用来了解该系统中的自旋动力学和退相干，并将磁关联的开始表征为偶极耦合强度增加的函数，偶极耦合强度随钬离子浓度的变化而变化。 对相关的有趣的混合单离子分子磁体铽二酞菁的研究也将进行。该项目是意大利帕维亚大学、法国格勒诺布尔路易斯尼尔实验室和波士顿学院研究小组的合作成果。 此外，ISIS——卢瑟福阿普尔顿实验室（英国）和保罗谢勒研究所（瑞士）的μ子用户设施将用于开展部分拟议研究。俄罗斯瓦维洛夫光学研究所和喀山国立大学的同事分别通过样品制造和理论分析为该项目提供了额外的科学支持。因此，拟议的工作将为美国研究生和本科生提供特殊的教育机会，通过对上述一些实验室的长期研究访问以及参加欧洲设施的核磁共振和介子光谱学的正式培训研讨会。此外，美国初级研究人员将获得分子磁性领域的宝贵经验，并熟悉美国目前代表性不足的μ子自旋光谱技术。该奖项由材料研究部和国际科学与工程办公室共同支持。