IMR: Development of a Transient Spectrometer for Education and Research into Quantum Coherence in Molecular Nanomagnets

IMR：开发用于分子纳米磁体量子相干性教育和研究的瞬态光谱仪

• 批准号: 0414809
• 负责人: Stephen Hill
• 金额: $ 19.8万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-15 至 2008-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0414809&HistoricalAwards=false
• 关键词: IMR; Development; Transient; Spectrometer; Education

This project will advance existing spectroscopic capabilities at the University of Florida (UF) and the National High Magnetic Field Laboratory (NHMFL) through the development of a unique broadband transient spectrometer which will be used for interdisciplinary collaborative research and student training. Experiments will focus on single-molecule magnets (SMMs), which represent a molecular approach to nanoscale and sub-nanoscale science, with potential applications in quantum computational devices. Very little is known about the coupling of such a nanomagnet to its environment, and how this coupling affects the coherence of quantum superposition states. Thus, we will develop a spectrometer capable of addressing questions relating to the quantum dynamics of molecule-based nanomagnets. A unique instrument will be developed, enabling: broadband continuous-wave frequency coverage (8 to 500 GHz); pump/probe and time domain capabilities (up to 300 GHz) with sub-microsecond resolution; and precise control over the DC magnetic field orientation. Experiments will include: rapid passage and transient EPR studies of magnetic quantum tunneling in SMMs; hole-burning and double resonance (ELDOR) investigations of quantum dephasing mechanisms in nanomagnets; and, ultimately, coherent control of the quantum spin states of SMMs. The new instrumentation will have important uses beyond the scope of the investigations described in this proposal, e.g. for high-resolution high-frequency EPR with applications in chemistry and even biology. The PI will collaborate with researchers at the NHMFL with the aim of developing a similar instrument for users of this facility. The PI is also involved in a range of outreach/education activities (related to an NSF CAREER award) which will benefit immensely from this project.%%%This project will build upon existing experimental capabilities available to researchers at the University of Florida (UF) and the National High Magnetic Field Laboratory (NHMFL) through the development of a new instrument which will be used for interdisciplinary collaborative research and student training. Experiments will focus on single-molecule magnets (SMMs), which represent a molecular approach to nanoscale science, with potential applications in quantum computing. The major hurdle in the development of a quantum computer is the so-called "decoherence" problem, whereby "quantum information" is irreversibly lost to the environment due to the simple fact that it is both impractical and impossible to completely isolate a quantum device from its surroundings. This decoherence can be studied using time-resolved magnetic or optical measurement techniques. Studies of SMMs will require capabilities covering a wide portion of the microwave frequency range, and with time resolution on the order of a fraction of a microsecond. Furthermore, an ability to control the quantum states of SMMs with a strong magnetic field is also needed. This project will address these pressing needs, resulting in a unique experimental instrument. The PI will collaborate with researchers at the NHMFL with the aim of developing similar capabilities for users of this national facility. In particular, the new instrumentation will have important uses beyond the research into the quantum properties of SMMs, e.g. for high-frequency electron paramagnetic resonance (EPR) studies of problems in chemistry and even biology. Finally, the PI is involved in a range of outreach/education activities (related to an NSF CAREER award) which will benefit immensely from the development of the new instrument.

该项目将通过开发独特的宽带瞬态光谱仪来提高佛罗里达大学（UF）和国家高磁场实验室（NHMFL）现有的光谱能力，该光谱仪将用于跨学科合作研究和学生培训。实验将集中在单分子磁体（SMM）上，它代表了纳米级和亚纳米级科学的分子方法，在量子计算设备中具有潜在的应用。关于这种纳米磁体与其环境的耦合，以及这种耦合如何影响量子叠加态的相干性，人们知之甚少。因此，我们将开发一种能够解决与基于分子的纳米磁体的量子动力学相关问题的光谱仪。将开发一种独特的仪器，实现： 宽带连续波频率覆盖（8 至 500 GHz）；具有亚微秒分辨率的泵浦/探头和时域功能（高达 300 GHz）；并精确控制直流磁场方向。实验将包括： SMM 中磁量子隧道的快速通过和瞬态 EPR 研究；纳米磁体中量子相移机制的烧孔和双共振（ELDOR）研究；最终，SMM 量子自旋态的相干控制。新仪器将具有超出本提案中描述的研究范围的重要用途，例如适用于化学甚至生物学应用的高分辨率高频 EPR。 PI 将与 NHMFL 的研究人员合作，旨在为该设施的用户开发类似的仪器。 PI 还参与了一系列外展/教育活动（与 NSF 职业奖相关），这些活动将从该项目中受益匪浅。%%%该项目将基于佛罗里达大学 (UF) 和国家强磁场实验室 (NHMFL) 研究人员现有的实验能力，开发一种用于跨学科合作研究和学生培训的新仪器。实验将集中在单分子磁体（SMM）上，它代表了纳米科学的分子方法，在量子计算中具有潜在的应用。量子计算机发展的主要障碍是所谓的“退相干”问题，即“量子信息”不可逆地丢失到环境中，因为将量子设备与其周围环境完全隔离是不切实际且不可能的。这种退相干可以使用时间分辨磁或光学测量技术来研究。 SMM 的研究需要能够覆盖微波频率范围的大部分，并且时间分辨率约为几分之一微秒。此外，还需要具有用强磁场控制SMM量子态的能力。该项目将解决这些紧迫的需求，从而产生一种独特的实验仪器。 PI 将与 NHMFL 的研究人员合作，旨在为该国家设施的用户开发类似的功能。特别是，除了研究 SMM 的量子特性之外，新仪器还将具有重要用途，例如用于化学甚至生物学问题的高频电子顺磁共振（EPR）研究。最后，PI 参与了一系列外展/教育活动（与 NSF 职业奖相关），这将从新仪器的开发中受益匪浅。