CAREER: Fundamental Investigation of the Wave Nature of Lattice Thermal Transport

职业：晶格热传输波性质的基础研究

基本信息

批准号：
2047109
负责人：
Yan Wang
金额：
$ 51.21万
依托单位：
Board of Regents, NSHE, obo University of Nevada, Reno
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-07-01 至 2026-12-31
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2047109&HistoricalAwards=false
关键词：
CAREER Fundamental Investigation Wave Nature

项目摘要

Heat transfer is a limiting factor in nanoscale engineering: if the finely tuned elements such as microchips or lasers get too hot or conduct heat uncontrollably, the devices will not function as intended. Thus, understanding how to control heat transfer at the nanoscale is critical in many engineering applications. Heat conduction in semiconductor crystals is dominated by collective atomic vibrations known as phonons. Conventionally, phonons are treated as particles that can propagate through a material, thus carrying heat, and can be scattered by material defects or other phonons. However, the wave nature of phonons can emerge or even dominate heat conduction in structures composed of periodically or quasi-periodically arranged components, e.g., quantum cascade lasers made of alternating layers of materials and integrated circuits containing densely packed nano-transistors. In those structures, the propagation of phonons can be promoted by constructive interference or halted by destructive interference. This project aims to explore these intriguing wave behaviors and elucidate the transition between particle-like and wave-like phonons through complementary computational and experimental techniques. This research will lead to novel engineering strategies to maximize heat dissipation in modern devices like quantum cascade lasers and integrated circuits or minimize heat conduction in thermoelectric materials and thermal barriers. This project will tightly integrate research, education, and outreach—including themed science exhibits, new curriculum development, hands-on research mentoring, and online course and research tool sharing—to have a broad, long-term impact on STEM education for K-12, undergraduate, and graduate students. The research objectives of this project are to: 1) rigorously understand the transport, scattering, and localization of wave-like phonons in periodic, quasi-periodic, and aperiodic structures, leveraging complementary spectral phonon analysis and phonon spectroscopy techniques; and 2) minimize lattice thermal transport through decoupled suppression of wave-like and particle-like phonon transport, leveraging machine learning-aided spectral phonon analysis and structure optimization. The proposed research on the wave nature of phonons can greatly advance the state of knowledge of thermal transport in crystalline solids, which has until now been primarily based on the particle nature of phonons. Such knowledge will enable the development of novel engineering strategies based on the wave nature of phonons, breaking the bottleneck of the thermal design or management of various heat transfer-limited technologies.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

传热是纳米级工程中的限制因素：如果微芯片或激光等细胞调谐的元素过热或无法控制地进行热量，则设备将无法按预期工作。在许多工程应用中，了解如何控制纳米级的传热至关重要。半导体晶体中的热传导以称为声子的集体原子振动为主。通常，声子被视为可以通过材料传播的颗粒，从而携带热，并且可以通过材料缺陷或其他声子散射。但是，声子的波性质可能会出现，甚至可以主导由定期或准周期排列的组件组成的结构中的热传导，例如，量子级联激光器由替代材料层和含有含糊不包装的纳米渗透剂的替代层层级别激光器制成。在这些结构中，可以通过建设性干扰来促进声子的传播，也可以因破坏性干扰而停止。该项目旨在探索这些有趣的波浪行为，并通过互补的计算和实验技术阐明粒子样和类似波浪的声子之间的过渡。这项研究将导致新型的工程策略，以最大程度地利用量子级联激光器和集成电路的现代设备中的热量消散，或者最大程度地减少热电材料和热屏障中的热传导。该项目将紧密整合研究，教育和外展活动，包括这些科学展览，新课程发展，动手研究心理以及在线课程和研究工具共享，对K-12，本科生和研究生的STEM教育产生了广泛的长期影响。该项目的研究目标是：1）严格地了解在周期性，准周期和上型结构中，波浪状声子的传输，散射和定位，利用完整的光谱声子分析和声子光谱技术；和2）通过脱耦的波动和粒子状的声子传输，利用机器学习辅助语音子分析和结构优化，减少晶格热传输。对声子的波性质的拟议研究可以很大程度上推进了晶体固体中热运输的知识状态，该奖项反映了NSF的坚定任务，并使用基金会的知识分子优点和更广泛的影响来审查标准，被认为是珍贵的支持。