Superfluid-inspired reconfigurable magnetic devices

信息的处理和传递是当今信息时代的中心任务。目前执行这项任务的设备需要越来越多的功率。另一方面，许多现代应用程序，如移动计算，没有大的电源来保持功能。这就产生了寻找处理和传输信息的替代方法的需要。超流动性，即没有耗散的连贯信息流，为这个问题提供了一个理想的解决方案。然而，在迄今为止所探索的材料中，超流动性仅限于低温。近年来，利用磁性材料高效电激励和热激励的进展，提出了室温磁性材料中存在超流体激发的现象。本项目的目标是利用这种超流体激励现象来提出和数值评估节能的超流体激励磁装置。特别是，首席研究员将构建约瑟夫森结的新型磁性类似物，这是传统低温信息处理和通信设备的基石。此外，利用磁性材料固有的长记忆和可调谐特性，也将探索超越传统约瑟夫森结的器件功能。在这个项目中，首席研究员将培训本科生和研究生，在现代材料建模，以提高美国？科学、技术、工程和数学人才。该研究旨在通过涵盖从新磁性材料的使用到应用驱动设备概念的设计和基准测试的各个方面来揭示新型超流体启发的磁性设备。为此目的，将追求下列具体目标：(a)受超导Josephson的启发，设计基于磁绝缘体的新型Josephson结；(b)利用自旋轨道和热磁力矩现象，开发通过磁性Josephson结（与超导Josephson结非常相似）的电和热偏置驱动自旋超流的电路理论；(c)利用电路理论组装磁性约瑟夫森结，以构建新型磁性器件，并对其进行经典到量子信息处理、通信和能量收集应用的基准测试。最后一个目标利用了基于超导约瑟夫森结的良好发展的器件概念，可以在我们提出的磁绝缘系统中进行模拟。此外，提出的磁性器件（电可重构和非易失性）增加了超导体器件中现有的功能，例如超越冯-诺伊曼内存计算架构的适应性。探索这些装置概念也将构成最后一个目标的一个组成部分。提出的方法首次将基于超流体的约瑟夫森现象与高于室温的磁体有序结合起来。通过利用磁铁的超流体特性，它为解决下一代信息处理和通信设备在高温下实现最小能量浪费的核心技术挑战开辟了全新的途径。在基本层面上，理论程序将作为一个独特的游乐场来测试和发现磁性，超导性和热电子界面的新现象。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.