Superfluid-inspired reconfigurable magnetic devices

处理和传输信息是当今信息时代的中心任务。目前执行此任务的设备需要越来越多的电力。另一方面，许多现代应用程序，如移动计算，无法使用大电源来保持功能。这就需要寻找处理和传输信息的替代手段。超流动性，即在没有耗散的情况下信息的连贯流动，为这个问题提供了一个理想的解决方案。然而，到目前为止，在探索的材料中，超流性仅限于低温温度。近年来，随着磁性材料高效电激发和热激发的发展，超流激发现象被提出存在于室温磁性材料中。该项目的目标是利用这种超流体激发的现象来提出和数值评估节能的超流体激发的磁性装置。特别是，主要的研究人员将构建新型的约瑟夫森结的磁性类似物，这是传统低温信息处理和通信设备的基础。此外，利用磁性材料具有固有的长记忆性和可调谐特性的事实，还将探索在传统约瑟夫森结中可能实现的器件功能。在这个项目中，首席研究员将在现代材料建模方面培训本科生和研究生，以加强美国？这项拟议的研究旨在通过涵盖从使用新的磁性材料到设计和基准应用驱动的设备概念的各个方面来揭开新型超流体启发的磁性设备的面纱。为此，将追求以下具体目标：(A)设计新颖的基于磁性绝缘体的约瑟夫森结，其灵感来自超导约瑟夫森结，(B)利用自旋轨道和热磁扭矩现象，开发电和热偏压驱动的自旋通过磁性约瑟夫森结的超流的电路理论，以及(C)使用电路理论组装磁性约瑟夫森结，以构建新型磁性设备，并对它们进行基准测试，用于经典到量子信息处理、通信和能量收集应用。最后一个目标利用了基于超导约瑟夫森结的成熟的器件概念，可以在我们提出的磁绝缘系统中模拟这种概念。此外，建议的磁性设备(可电重新配置和非易失性)增加了基于超导体的设备现有功能之外的功能，例如超越冯-诺伊曼内存计算体系结构的适应性。探索这样的设备概念也将成为最后一个目标的组成部分。提出的方法首次将基于超流的约瑟夫森现象与高于室温的磁体有序化相结合。通过利用磁体的类似超流体的特性，它开辟了全新的途径，以解决下一代信息处理和通信设备在高温下实现最低能量损耗的核心技术挑战。在基本层面上，该理论计划将作为一个独特的游乐场，测试和发现磁性、超导和热电子学界面上的新现象。该奖项反映了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。

Processing and transporting information are the central tasks in today's age of information. Current devices that perform this task require increasing amount of power. Many modern applications, such as mobile computing, on the other hand, does not have access to large power sources to remain functional. This has created a need to search for alternate means to process and transport information. Superfluidity, that is coherent flow of information in the absence of dissipation, provides an ideal solution to this problem. However, in materials explored so far, the superfluidity has been limited to cryogenic temperatures. Recently, taking advantage of the advancement of efficient electrical and thermal excitation of magnetic materials, phenomena inspired from superfluidity have been proposed to exist in room temperature magnetic materials. The goal of this project is to utilize such superfluid-inspired phenomena to propose and numerically evaluate energy-efficient superfluid-inspired magnetic devices. In particular, the prinicipal investigator will construct novel magnetic analogues of Josephson junctions, which are the building blocks of conventional cryogenic information processing and communication devices. Moreover, exploiting the fact that magnetic materials have inherently long memory and tunable properties, device functionality beyond those possible in conventional Josephson junctions will also be explored. During this project, the principal investigator will train undergraduate and graduate students, in modern materials modelling, for enhancing the United States? science, technology, engineering and math workforce.The proposed research aims at unraveling novel superfluid-inspired magnetic devices by covering aspects-starting from the use of new magnetic materials to designing and benchmarking of application-driven device concepts. For this purpose, the following specific objectives will be pursued: (a) designing novel magnetic insulator-based Josephson junctions which are inspired from superconducting Josephson, (b) developing circuit theory for electrical and thermal bias driven superflow of spin through magnetic Josephson junctions (in close analogy to superconducting Josephson junctions) utilizing the phenomena of spin-orbit and thermomagnonic torques, and (c) using the circuit theory to assemble magnetic Josephson junctions for constructing new class of magnetic devices and benchmarking them for classical to quantum information processing, communication and energy harvesting applications. The last objective takes advantage of the well-developed device concepts based on superconducting Josephson Junctions, which can be mimicked within our proposed magnetic insulating systems. In addition, the proposed magnetic devices (being electrically reconfigurable and nonvolatile) add functionality beyond those existing in superconductor-based devices, such as amenability to beyond von-Neumann in-memory computing architectures. Exploring such device concepts will also form an integral part of the last objective. The proposed approach combines, for the first time, superfluid-based Josephson phenomena with above room temperature ordering of magnets. By tapping into superfluid-like properties of magnets, it opens up completely new avenues to solve the central technical challenge of achieving minimal energy wastage at high operating temperature for the next-generation information processing and communication devices. On a fundamental level, the theoretical program will serve as a unique playground to test and discover new phenomena at the interface of magnetism, superconductivity and caloritronics.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.