NSF/DMR/-BSF: Universality and Control of Wave Propagation Inside Random Media

NSF/DMR/-BSF：随机介质内波传播的普遍性和控制

• 批准号: 1609218
• 负责人: Azriel Genack
• 金额: $ 45万
• 依托单位: CUNY Queens College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-15 至 2019-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1609218&HistoricalAwards=false
• 关键词: NSF; DMR; BSF; Universality; Control

Nontechnical Abstract: The scattering of waves, whether acoustic, radio or optical, is an inescapable part of our environment. When this environment is disordered the wave can scatter along many different paths and this can impair our ability to communicate or to image or excite electronic circuits. This project will study the propagation of waves through disordered media using a combination of experimental approaches supplanted by theory and simulations. The effort is a collaboration between the PI and the group of Patrick Sebbah at Bar-Ilan University as part of the NSF/DMR-BSF program. The work will focus on developing a universal description of wave propagation in finite random media and will provide an excellent training ground for students. The results of this work will also have a broad impact on a range of interdisciplinary problems in condensed matter physics, acoustics and optics.Technical Abstract: The proposed research extends the range of a universal description of wave propagation from the reflected and transmitted wave at the boundaries of disordered media into the interior of the sample and from samples many times thicker than the mean free path to samples so thin that propagation is nearly ballistic. Phenomenological properties of transmission, such as the extrapolation length, upon which the scaling of transmission depends, will be related to universal parameters such as auxiliary localization lengths of different transmission eigenchannels. These parameters depend only on the ratio of sample length and the localization length and the eigenchannel number. An important aspect of the research is finding the relationship between the transmission eigenchannels, modes of waves in the medium, and solutions of a generalized diffusion equation with a position-dependent diffusion coefficient. The relationship between these approaches provides key clues to the control the wave within random media and disordered metamaterials. Such control of the wave inside disordered media provides a path towards improved imaging, resource exploration, local heating within the body, telecommunications, and low-threshold random lasing. The characteristics of a new class of quasi-one dimensional scattering sample, in which the local density of states vanishes in the interior of the sample, is investigated to understand the relationship of the density of states and localization. This provides new pathways to localizing waves and isolating regions from the surrounding environment.

非技术摘要：波的散射，无论是声学，无线电或光学，是我们的环境中不可避免的一部分。 当这种环境是无序的，波可以沿着沿着许多不同的路径散射，这会损害我们的通信能力或成像或激发电子电路的能力。 该项目将使用由理论和模拟取代的实验方法相结合来研究波通过无序介质的传播。 这项工作是PI和Bar-Ilan大学的帕特里克·塞巴小组之间的合作，是NSF/DMR-BSF计划的一部分。 这项工作将集中在开发一个通用的描述波在有限随机介质中的传播，并将为学生提供一个很好的培训基地。 这项工作的结果也将对凝聚态物理学、声学和光学领域的一系列跨学科问题产生广泛的影响。技术摘要：拟议的研究将波传播的普遍描述的范围从无序介质边界处的反射和透射波扩展到样品内部，从比平均自由程厚许多倍的样品扩展到如此薄的样品，传播几乎是弹道式的。传输的现象学特性（例如传输缩放所依赖的外推长度）将与通用参数（例如不同传输本征通道的辅助定位长度）相关。这些参数仅取决于样本长度与局部化长度之比以及本征通道数。研究的一个重要方面是找到传输本征通道，波在介质中的模式，和广义扩散方程的位置依赖的扩散系数的解决方案之间的关系。这些方法之间的关系为控制随机介质和无序超材料中的波提供了关键线索。这种对无序介质内的波的控制为改善成像、资源勘探、体内局部加热、电信和低阈值随机激光提供了一条途径。研究了一类新的准一维散射样品的特性，其中局域态密度在样品内部为零，以了解态密度与局域化的关系。这为定位波和将区域与周围环境隔离提供了新的途径。