Asymmetric Wave Propagation in Non-Hamiltonian Structures

非技术摘要该奖项支持研究和教育以高效和可重新配置的方式开发控制和管理电波传播的新概念，例如无线电波或光波。增益机制增强信号并帮助传输信息，而损耗通常被认为会降低性能，因此应该避免。该项目的目标是开发新的材料和电路设计，仔细平衡增益和损耗，并基于看似无关的物理领域的基本理论概念，这些领域在本文中没有表达出来，以控制波的传播。投资者指数将探索得失的相互作用，以及出现的不寻常和意想不到的现象。在这一过程中，研究将产生新的电子电路和媒体设计策略，以有效地处理电子、光学或更一般的电磁信号。研究团队由理论和实验教师和学生组成，将平等地将计算方法与实验实际结合起来，帮助指导理论发展的重点和语言。实验部分围绕着在概念上直截了当的电子模拟的背景下探索理论概念。除了产生合理的理论结果外，还将产生一批稳定的基于工程但在理论上精通的物理学家。技术摘要该项目将发展元素构建块的基础物理，这些构建块能够作为独立设备或阵列的复制单元来诱导可重新配置的不对称波传输。这将通过战略引入的非埃尔米特元素的相互作用来实现，这些元素可能包括非线性和时间依赖性。所提出的策略是基于时空反射或PT对称性的变化。这些想法最初是在量子力学领域内发展起来的，由于其有用性令人怀疑，因此对经典波力学具有开创性的适用性，尽管通过实验获得的途径仍然是一个挑战。该研究小组将在理论与实验紧密结合的等效电子模拟领域内采用实验方法来发展几个新的方面，包括：(I)非厄米散射，时间相关的散射，在多模阵列中表现出方向相关的不可见性或模式选择增益，(Ii)非厄米非线性系统的高品质因数定向散射，其中基频的透射率增强，而不是减小；(Iii)在由陀螺有源结构诱导的线性系统中使用完美阻抗匹配的隔离和单向吸收；和(Iv)快速状态操纵，其中PT对称性允许方向相关的加速伪哈密顿动力学。开发的策略将允许在更复杂的应用中有效地预测行为，例如有源天线阵列、电声集成或复杂的超材料阵列，因为它们不可避免地迁移到非厄米系统固有的有源元件领域。如果基本理论和随之而来的设计方法在这个更透明的电子环境中得到很好的基础，这些最终应用将变得不那么具有挑战性。由理论和实验教师和学生组成的研究团队将同样将计算方法与实验现实结合起来，帮助指导理论的重点和语言的发展。除了产生合理的理论结果外，还将产生一批稳定的以工程为基础、但在理论上精通的物理学家。本科生和研究生除了通过团队建立的网络形成国际合作前景外，还将在分析、数值计算和实验方法方面获得灵活和可移植的技能。

Nontechnical AbstractThis award supports research and education to develop new concepts for the control and management of wave propagation, for example radio or light waves, in efficient and reconfigurable ways. Gain mechanisms boost signals and help to transfer information, whereas loss is generally considered to degrade performance and so is to be avoided. The goal of this project is to develop new materials and circuit designs that carefully balance gain and loss and are based on fundamental theoretical concepts from seemingly unrelated areas of physics that have not been expressed in this context to control wave propagation. The PIs will explore the interplay of gain and loss and the unusual and unexpected phenomena that emerges. In the process, the research will result in new electronic circuit and media design strategies for efficient manipulation of electronic, optical, or more generally electromagnetic signals. The research team, consisting of both theoretical and experimental faculty and students, will equally engage computational methods with experimental realities helping to guide the focus and language of the theory as it develops. The experimental component revolves around exploring theoretical concepts within the context of conceptually straightforward electronic analogs. In addition to generating sound theoretical results, a steady stream of engineering based, yet theoretically savvy physicists will be produced.Technical AbstractThis project will develop the fundamental physics of elemental building blocks that are uniquely capable of inducing reconfigurable asymmetric wave transport as either stand-alone devices or as duplicated units of arrays. This will be achieved via the interplay of strategically introduced non-Hermitian elements that can include nonlinearities and time dependence. The proposed strategies are based on variations of space-time reflection, or PT symmetry. Originally developed within the realm of quantum mechanics, were its usefulness is dubious, the ideas have had groundbreaking applicability to classical wave mechanics, although experimentally accessible avenues remain a challenge. This research group will use an experimental approach within the realm of equivalent electronic analogs in a tight-knit theoretical-experimental collaboration to develop several new aspects, including : (i) non-Hermitian, time-dependent scattering, exhibiting directional-dependent invisibility or mode-selective gain in multimode arrays, (ii) high figure of merit directional scattering from non-Hermitian nonlinear systems where the transmittance intensity of the fundamental frequency is enhanced, rather than diminished; (iii) the use of perfect impedance-matched isolation and unidirectional absorption in linear systems induced by gyro-active structures; and (iv) rapid state manipulation where PT-symmetry allows for directionally dependent accelerated pseudo-Hamiltonian dynamics. The strategies developed will allow for efficient prediction of the behavior in more complicated applications such as active antenna arrays, electro-acoustic integration, or complex metamaterial arrays, as they inevitably migrate into the realm of active elements inherent in non-Hermitian systems. These ultimate applications will become significantly less challenging if the fundamental theory and consequent design approaches are well grounded within this more transparent electronic context.The research team, consisting of both theoretical and experimental faculty and students, will equally engage computational methods with experimental realities helping to guide the focus and language of the theory as it develops. In addition to generating sound theoretical results, a steady stream of engineering based, yet theoretically savvy physicists will be produced. Both undergraduate and graduate students will acquire flexible and transferable skills in analytics, numerical computation, and experimental methods, in addition to forming international collaborative prospects through the team's established network.