Harnessing Magnonic Nonreciprocity Through Dissipation Engineering

传统上，系统与环境相互作用产生的能量耗散一直被视为限制信号寿命的唯一敌人。然而，新理论的出现重塑了我们对它的看法，并使新的工程方法能够利用耗散作为操纵给定系统行为的重要资源。尽管耗散工程在光子学和电子学方面取得了突飞猛进的进展，但在磁子和混合磁子系统中，耗散工程仍然是一种主要的理论追求，在这些系统中，信息是由磁子携带的--基本的集体自旋激发。特别是，对与非互易性交织在一起的独特耗散现象的实验探索，如健壮的模式转换和非厄米特集肤效应，仍处于起步阶段，缺乏精心设计的实验和通向实际应用的明确路径。这个项目将研究磁子系统中耗散的基本原理和操纵耗散的工程方法。这些努力将极大地加强对耗散如何在磁子系统中发挥作用的基本理解，导致在实际应用中的进步，如非互易信息处理。该项目将为本科生和研究生提供广泛的指导和培训机会，此外，还将为本科生引入新的课程课程，为未被充分代表的高中生群体和K-12学生创造新的机会，让他们沉浸在科学和参与研究中。该项目旨在通过利用混合磁铁系统中的耗散工程来利用非互惠。通过理论指导的实验工作，强耦合微波光子-磁振子系统将分三个并行推进：推力1将集中在混合磁振子系统中两个磁振子模式之间的模式转换的原理证明，这是由系统的拓扑保护的，因此具有很高的鲁棒性。这将在使用脉冲操作的时间域中实现。推力2将研究磁振子和微波光子模式之间的拓扑模转换，这将在连续波操作下在空间域实现。《推力3》将演示由耗散耦合实现的混合磁子系统中集肤效应的出现。这项研究将为有关磁系统的耗散、奇点包围的动力学、非厄米集肤效应和非互易输运之间的关系以及非线性在磁化动力学中的作用等一系列基本问题提供深入的见解。研究成果将为在从神经形态计算到基于磁振子的逻辑系统的各种应用中利用混合磁振子的独特的非厄米特性质铺平道路。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Energy dissipation resulting from the interaction of a system with its environment has been traditionally viewed solely as a foe that limits signal lifetimes. However, the advent of new theories has reshaped our perspective on it and enabled novel engineering approaches to utilize dissipation as an important resource for manipulating the behaviors of a given system. Despite its rapid advancements in photonic and electronic circuits, dissipation engineering remains primarily a theoretical pursuit in magnonic and hybrid magnonic systems where information is carried by magnons – the elementary collective spin excitations. In particular, the experimental exploration of unique dissipation phenomena intertwined with nonreciprocity, such as robust mode conversion and the non-Hermitian skin effect, is still in its infancy, lacking well-designed experiments and a clear path toward practical applications. This project will investigate the basic principles of dissipations in magnonic systems and engineering approaches for manipulating dissipations. These endeavors will greatly enhance the fundamental comprehension of how dissipation functions within magnonic systems, leading to advancements in practical applications such as nonreciprocal information processing. The project will provide extensive mentoring and training opportunities for undergraduate and graduate students, and moreover, a new course curriculum will be introduced for undergraduate students, creating new opportunities for underrepresented high school student groups and K-12 students to immerse themselves in science and participate in research.This project aims to harness nonreciprocity by leveraging dissipation engineering in hybrid magnonic systems. Through theory-guided experimental efforts, strongly coupled microwave photon-magnon systems will be explored in three parallel thrusts: Thrust 1 will focus on the proof-of-principle demonstration of mode conversion between two magnon modes in hybrid magnonic systems, which is protected by the topology of the system and thus highly robust. This will be achieved in the time domain using pulsed operations. Thrust 2 will investigate the topological mode conversion between a magnon and a microwave photon mode, which will be implemented in the space domain under continuous wave operation. Thrust 3 will demonstrate the emergence of the skin effect in a hybrid magnonic system that is enabled by dissipative coupling. This research will provide insights for a series of fundamental questions related to the dissipation of magnetic systems, the dynamics of encircling singularity points, the relation between the non-Hermitian skin effect and nonreciprocal transport, and the role of the nonlinearities that are naturally built in the magnetization dynamics. The research outcome will pave the way for leveraging the unique non-Hermitian properties of hybrid magnonics across various applications, ranging from neuromorphic computing to magnon-based logic systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.