Phonon Heat Transport and Mechanical Oscillations in Mesoscopic Systems

介观系统中的声子热传输和机械振荡

• 批准号: 9873573
• 负责人: Michael Cross
• 金额: $ 27万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-01-15 至 2003-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9873573&HistoricalAwards=false
• 关键词: Phonon; Heat; Transport; Mechanical; Oscillations

9873573CrossThis award supports theoretical research and education that aims to investigate the transport of heat by phonons and mechanical oscillations in fabricated structures of GaAs and silicon on the 10-100 nm length scale. Recent advances in microfabrication techniques have allowed the construction of suspended, free-standing structures of insulating or doped GaAs or silicon. Portions of these structures are isolated from the substrate so that the only thermal pathway to the environment is through the suspension "beams." These beams are defined lithographically, so they can be designed to allow measurements of thermal transport at the mesoscopic scale. Thermal pathways of rectangular cross-section 200 X 300 nm and length 5m have already been constructed, and much smaller widths seem feasible. The mechanical oscillations of these structures can also be studied experimentally. These advances promise the first systematic investigation of heat transport by phonons in mesoscopic systems, and further development in the study of mechanical oscillations in mesoscopic systems which is poorly understood. The PI proposes a theoretical attack on these problems. The PI plans to extend their recent work based on the Landuaer-Buttiker formalism. Realistic models of phonons that will allow the quantitative prediction of thermal transport will be used and the effects of scattering by geometry, surface roughness, and material disorder will be included. Electron-phonon interaction effects, which can also be studied in experimental geometries, will be investigated. At low temperatures, the modes containing the thermal energy become the mechanical oscillation modes of the suspended structures, so that studies of heat transport and dissipation in mechanical oscillators becomes closely related. Thus it is possible to extend the theoretical investigation to mesoscopic oscillators, and in particular the Q of such oscillators.%%%This award supports research and education in an area that is both fundamental science and related to MEMS (microelectromechanical systems). The PI will use state of the art techniques to study vibrations and oscillations and the flow of heat in mechanical systems fabricated from silicon and other materials on micron and sub-micron length scales.***

9873573 Crossthis Award支持理论研究和教育，旨在调查GAAS和硅在10-100 nm长度尺度上使用声子和机械振荡的热量运输以及机械振荡。 微型制造技术的最新进展允许建造悬浮的，独立的绝缘或掺杂的GAAS或硅的结构。 这些结构的一部分与底物分离出来，因此通往环境的唯一热途径是通过悬架“梁”。 这些梁是在正版上定义的，因此可以设计它们以允许在介质刻度上测量热传输。 矩形横截面的热路径200 x 300 nm和长度为5M，并且宽度较小似乎是可行的。 这些结构的机械振荡也可以实验研究。 这些进步有望在介观系统中首次对声子进行热传输的系统研究，并在研究中尚不清楚的介质系统中的机械振荡研究中进一步发展。 PI提出了对这些问题的理论攻击。 PI计划根据Landuaer-Buttiker形式主义扩展他们最近的工作。 将使用允许允许热传输定量预测的声子的现实模型，并将包括几何形状，表面粗糙度和材料障碍的散射影响。 将研究在实验几何形状中也可以研究的电子相互作用效应。 在低温下，包含热能的模式成为悬浮结构的机械振荡模式，因此机械振荡器中的热传输和耗散的研究变得密切相关。 因此，可以将理论研究扩展到介观振荡器，尤其是此类振荡器的Q。%% %%该奖项支持与MEMS（MEMSS（Microelectromenerical Systems））有关的领域的研究和教育。 PI将使用最先进的技术来研究由硅和微米长度尺度上硅和其他材料制造的机械系统中的振动和振荡流。***