Chemical control of spin-phonon coupling and magnetisation dynamics

自旋声子耦合和磁化动力学的化学控制

• 批准号: 2105188
• 金额: --
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2105188
• 关键词: Chemical; control; spin; phonon; coupling

Manufacturing new technologies with bottom-up approaches could lead to reductions in device size with increased energy efficiency. An example is the use of molecules for binary data storage, which requires data to be non-volatile at temperatures achievable with economical cooling requirements; a common benchmark is the temperature of liquid nitrogen (77 K). We have recently made a step-change by raising the temperature at which molecular memory can be observed from 14 K to 60 K in a dysprosocenium single-molecule magnet (SMM) (Goodwin, Ortu, Reta, Chilton and Mills, Nature, 2017, 548, 439). Interaction of the molecular electronic spin with its environment (spin-phonon coupling) is a critically limiting feature for SMM performance, as it leads to magnetic relaxation and the loss of magnetic information. To realise molecule-based high-density data storage, we must control the spin-phonon coupling.We recently developed a computational method for calculating spin-phonon coupling and employed it to show that magnetic relaxation in dysprosocenium at high temperatures is due to localised molecular vibrations, with four vibrational modes being particularly important. This project will employ our computational method to develop general strategies for controlling the spin-phonon coupling in SMMs, leading to targeted design of SMMs displaying magnetic memory at higher temperatures, and thus delivering technologically viable candidates for molecule-based high-density data storage.The objectives are:(i) to understand how molecular structure influences vibrational spectrum (ii) to understand how spin-phonon coupling can be modulated by molecular structure(iii) to determine design criteria for improved SMMsThese objectives will be achieved by:(i) employing density-functional theory calculations on hypothetical molecules to catalogue structure-vibration relationship(ii) employing our spin-phonon coupling method to determine how magnetic relaxation is influenced by vibrational profileThis project is directly relevant to the EPSRC "Physical Sciences" and "Quantum Technologies" research themes, specifically to the "Physics grand challenge(s)" of "Quantum Physics for New Quantum Technologies" and "Nanoscale Design of Functional Materials", and the "Chemical sciences and engineering grand challenge" of "Directed Assembly of Extended Structures with Targeted Properties".

采用自下而上的方法制造新技术可以减少设备尺寸，提高能源效率。一个例子是使用分子进行二进制数据存储，这要求数据在经济的冷却要求下可以达到的温度下是非易失性的;一个常见的基准是液氮的温度（77 K）。我们最近通过将在镝单分子磁体（SMM）中可以观察到分子记忆的温度从14 K提高到60 K来进行阶跃变化（Goodwin，Ortu，Reta，Chilton和米尔斯，自然，2017，548，439）。分子电子自旋与其环境的相互作用（自旋-声子耦合）是SMM性能的关键限制特征，因为它导致磁弛豫和磁信息的丢失。为了实现基于分子的高密度数据存储，我们必须控制自旋-声子耦合，我们最近开发了一种计算自旋-声子耦合的计算方法，并使用它来显示在高温下的dysprosocenium的磁弛豫是由于局域分子振动，其中四个振动模式是特别重要的。该项目将采用我们的计算方法来开发控制SMM中自旋-声子耦合的通用策略，从而有针对性地设计在更高温度下显示磁存储器的SMM，从而为基于分子的高密度数据存储提供技术上可行的候选方案。目标是：（i）了解分子结构如何影响振动光谱（ii）了解分子结构如何调制自旋-声子耦合（iii）确定改进SMM的设计标准。这些目标将通过以下方式实现：（i）采用密度泛函理论计算假想分子的目录结构振动关系（ii）采用我们的自旋-声子耦合方法来确定磁弛豫是如何受到振动分布的影响这个项目是直接相关的EPSRC“物理科学”和“量子技术”的研究主题，特别是“新量子技术的量子物理学”和“功能材料的纳米级设计”的“物理学大挑战”，以及“具有目标性质的扩展结构的定向组装”的“化学科学和工程大挑战”。