Acoustic Resonances in Solids: Pressure-, Spatial- and Photo-tuning

凝聚态物理项目将开发一种新的激光散射技术来测量材料的弹性常数，在金刚石砧细胞中可以达到兆棒压力。这项研究是基于对由于表面波纹效应而产生的驻波共振的检测。该技术对不透明材料的研究特别有用，并将应用于地球物理学中重要的关键材料。实验提出，应提供见解的物理变形机制和弹性特性相关的埋藏界面和嵌入层状结构。这些系统中声波的频率分布和空间限制将为声波器件的应用提供新的机会。此外，还将研究一种新的光改性玻璃的不同寻常的机械性能，这种玻璃在二元硫系玻璃中稳定在最佳连接状态。同样令人感兴趣的是机械稳定性和与原子之间局部连通性相关的明显玻璃形成倾向之间的重要相互作用。该项目将培养研究生和本科生在当代固体物理学的挑战性问题。他们将获得现代激光光谱学技术的宝贵经验。这种教育将为他们在学术界或工业界的富有成效的职业生涯做好准备。该项目将支持固体声学和力学性能的激光光谱研究。这项研究涉及材料在极端压缩下的行为——接近地球内部的压力。它将开发一种新的方法来探测材料的高压行为，并将为材料结构性能理论提供关键参数。对埋藏层内高频声波的研究将为局部激励物理学提供重要的信息。波的频率分布和空间限制将产生新的技术机会，而不会受到传统表面波设备带宽限制的影响。提出的研究的玻璃解决了他们的弹性和光学性质的关键方面，通过创建一个新的，光修饰，状态。令人感兴趣的是这种状态的性质如何与玻璃的形成有关，以及玻璃的性质如何取决于原子的特定局部连通性。再加上玻璃的非结晶性所带来的自由和灵活性，这种不寻常的光致效应可能会在这些有用的材料中产生具有技术价值的结果。本研究将在研究生和本科生的帮助下进行。他们将通过参与固态物理和激光光谱技术的当代前沿研究获得宝贵的经验。这些经验将对他们的进一步学习，或在工业，学术或政府实验室的就业有很大的价值。

The condensed matter physics project will develop a new laser light scattering technique to measure the elastic constants of materials up to mega-bar pressures achievable in a diamond anvil cell. The research is based on the detection of standing wave resonances that develop because of surface corrugation effects. The technique is particularly useful for studies of opaque materials and will be applied to key materials important in geophysics. Experiments are proposed that should provide insights into the physics of poorly understood deformation mechanisms and elastic properties associated with buried interfaces and embedded laminar structures. The frequency profile and spatial confinement of acoustic waves confined in these systems will yield new opportunities for acoustic wave device applications. In addition, the unusual mechanical properties of a new, photo-modified, state of glass that is stabilized at optimum connectivity in binary chalcogenide glasses will be investigated. Also of interest is the important interplay between mechanical stability and pronounced glass forming tendencies related to local connectivity between atoms. The project will train graduate and undergraduate students in challenging issues in contemporary solid state physics. They will gain valuable experience with modern laser spectroscopy techniques. This education will prepare them for productive careers in academia or industry.The project will support a laser spectroscopy study of the acoustic and mechanical properties of solids. The research involves the behavior of materials under extreme compression - approaching pressures at the Earth's interior. It will develop a new method to probe high-pressure behavior of materials and will yield critical parameters for theories of material structural properties. The study dealing with high frequency acoustic waves confined to buried layers should provide important information into the physics of localized excitations. The frequency profile and spatial confinement of the waves will yield new technological opportunities that will not suffer from bandwidth limitations of conventional surface wave devices. The proposed study of glasses addresses key aspects of their elastic and optical properties through creation of a new, photo-modified, state. Of interest is how the properties of this state relate to the formation of glasses and how glass properties depend on the specific local connectivity of atoms. Together with the freedom and flexibility associated with the non-crystalline nature of glasses, the unusual light-induced effects may yield results of technological value in these useful materials. This research will be conducted with the aid of graduate and undergraduate students. They will gain valuable experience through their involvement in contemporary forefront research in solid state physics and laser spectroscopy techniques. These experiences will be of great value in their further studies, or employment in industry, academia or government laboratories.