2-Output Spin Wave Programmable Logic Gate

Abstract

This paper presents a 2-output Spin-Wave Programmable Logic Gate structure able to simultaneously evaluate any pair of AND, NAND, OR, NOR, XOR, and XNOR Boolean functions. Our proposal provides the means for fanout achievement within the Spin Wave computation domain and energy and area savings as two different functions can be simultaneously evaluated on the same input data. We validate our proposal by means of Object Oriented Micromagnetic Framework (OOMMF) simulations and demonstrate that by phase and magnetization threshold output sensing {AND, OR, NAND, NOR} and {XOR and XNOR} functionalities can be achieved, respectively. To get inside into the potential practical implications of our approach we use the proposed gate to implement a 3-input Majority gate, which we evaluate and compare with state of the art equivalent implementations in terms of area, delay, and energy consumptions. Our estimations indicate that the proposed gate provides 33% and 16% energy and area reduction, respectively, when compared with spin-wave counterpart and 42% energy reduction while consuming 12x less area when compared to a 15 nm CMOS implementation.

A Spin Wave-Based Approximate 4:2 Compressor: Seeking the most energy-efficient digital computing paradigm

“…As a result, different technologies have been investigated to replace CMOSs, such as graphene devices [3], memristors [4], and spintronics [5]. In this article, we study one type of spintronics-SW technology-that appears to open the way toward the most energy-efficient digital computing paradigm [6]- [9]. SW-based computing is promising for three main reasons [6]- [9]: 1) it has ultralow energy consumption potential because it does not rely on electron movements but on spinning around the magnetic field orientation [6]- [9], 2) it is highly scalable because SWs' wavelength can reach the nanometer scale [6]- [9], and 3) it has an acceptable delay [6]- [9].…”

“…In this article, we study one type of spintronics-SW technology-that appears to open the way toward the most energy-efficient digital computing paradigm [6]- [9]. SW-based computing is promising for three main reasons [6]- [9]: 1) it has ultralow energy consumption potential because it does not rely on electron movements but on spinning around the magnetic field orientation [6]- [9], 2) it is highly scalable because SWs' wavelength can reach the nanometer scale [6]- [9], and 3) it has an acceptable delay [6]- [9]. As a consequence of these promising features, different research groups have made use of SW interaction to build logic gates and circuits.…”

“…The first experimental SW logic gate was an inverter designed by utilizing a Mach-Zehnder interferometer [10]. Moreover, the Mach-Zehnder interferometer has been used to build single-output majority, (N)AND, (N)OR, and X(N) OR gates [10], while multioutput SW logic gates have been introduced in [9] and [11]- [13]. Furthermore, multifrequency logic gates that enhance SW computing and storage capabilities have been proposed in [8] and [14], and wave pipelining has been achieved with pulse mode operation in the SW domain by employing four cascaded majority gates [15].…”