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.
