Nonlinear Spin Waves in Magnetic Films: New Concepts and Applications

混沌和孤子是非线性科学的两个重要分支，吸引了包括数学、物理学、生物学和工程学在内的广泛学科的兴趣。 混沌是一种结果对初始条件高度敏感的想法：一只蝴蝶在纽约扇动翅膀，东京有一场风暴。 孤立子是一种类似海啸的局域波，经常出现在弱非线性系统中。 通常人们认为混沌和孤子是对立的。孤立子可以受到强烈扰动，但仍然存在，例如，使得难以阻止海啸。 这个项目将寻找混沌和孤子之间的联系。 具体来说，该项目将利用磁膜系统中的自旋波（磁序中的一种移动扰动）来探索这些联系。 在应用方面，该项目将开发一种新的安全通信方案，利用反馈环中的孤子。 这是两所大学的一个实验组和一个理论组之间的联合计划。通过对学生进行实验和理论非线性动力学方法的培训，该项目将帮助年轻科学家跨越以下鸿沟：理论地？和物理现实，导致更好的实验和更好的理论。 教育部分还包括将非线性动力学和混沌纳入本科和研究生课程，并向科罗拉多贫困高中的学生伸出援手。技术摘要 * 该项目将利用磁膜系统中的自旋波来探索孤立子和混沌之间可能的交叉。 该项目将探索？混沌载波孤子?孤子与混沌载波。 磁动力学探针将被用来研究混沌自旋波脉冲的演化和从这样的脉冲的包络孤子的形成。 该项目还将探索？混沌孤子?具有相干载波但在时间上表现出混沌行为的孤子。 研究内容包括调制不稳定性对混沌孤子的激发以及磁膜反馈环中的混沌孤子。 在应用方面，该项目将开发一种新的安全通信方案，利用反馈环中的孤子相关费米-帕斯塔-乌拉姆递归。 对于所有的项目，理论建模将激励，支持和解释实验工作。 教育部分的重点是通过核心课程和新的选修课的设计，以及本科生和研究生研究人员的培训和接触到贫困高中的学生，将非线性动力学和混沌纳入本科生和研究生课程。

****NON-TECHNICAL ABSTRACT**** Chaos and solitons are two important branches of nonlinear science that have attracted interest over a wide range of disciplines, including mathematics, physics, biology, and engineering. Chaos is the idea that outcomes are highly sensitive to initial conditions: a butterfly flaps its wings in New York and there is a storm in Tokyo. Solitons are localized waves like tsunamis, and frequently occur in weakly nonlinear systems. Usually one believes that chaos and solitons are opposed to each other ? a soliton can be strongly perturbed and yet persists, for example, making it difficult to stop, say, a tsunami. This project will seek connections between chaos and solitons. Specifically, the project will take advantage of spin waves (a travelling disturbance in the magnetic order) in magnetic film systems to explore these connections. On the applied side, the project will develop a new secure communication scheme that exploits the solitons in feedback rings. This is a joint program between one experimental group and one theoretical group in two universities. Through the training of students in both experimental and theoretical nonlinear dynamical methods, the project will help young scientists cross the divide between ?theory land? and physical reality, leading to both better experiments and better theories. The education portion also includes the incorporation of nonlinear dynamics and chaos into undergraduate and graduate curricula and reaching out to students in disadvantaged high schools in Colorado.****TECHNICAL ABSTRACT****This project will take advantage of spin waves in magnetic film systems to explore a possible crossover between solitons and chaos. The project will explore ?chaotic carrier solitons? ? solitons with chaotic carrier waves. A magneto-dynamic probe will be used to study the evolution of a pulse of chaotic spin waves and the formation of an envelope soliton from such a pulse. The project will also explore ?chaotic solitons? ? solitons that have coherent carrier waves but exhibit chaotic behaviors in time. The work will include the study of chaotic soliton excitation through modulational instability and chaotic solitons in magnetic film feedback rings. On the applied side, the project will develop a new secure communication scheme that exploits the soliton-associated Fermi-Pasta-Ulam recurrence in feedback rings. For all the projects, theoretical modeling will inspire, support, and interpret experimental work. The education portion focuses on the incorporation of nonlinear dynamics and chaos into undergraduate and graduate curricula both through core courses and through the design of new electives, as well as training of undergraduate and graduate researchers and reaching out to students in disadvantaged high schools.