Non-volatile Clocked Spin Wave Interconnect for Beyond-CMOS Nanomagnet Pipelines.

Sourav Dutta,Azad Naeemi,Dmitri E Nikonov,Ian A Young,Sasikanth Manipatruni,Nickvash Kani,Sou-Chi Chang

doi:10.1038/srep09861

Abstract

The possibility of using spin waves for information transmission and processing has been an area of active research due to the unique ability to manipulate the amplitude and phase of the spin waves for building complex logic circuits with less physical resources and low power consumption. Previous proposals on spin wave logic circuits have suggested the idea of utilizing the magneto-electric effect for spin wave amplification and amplitude- or phase-dependent switching of magneto-electric cells. Here, we propose a comprehensive scheme for building a clocked non-volatile spin wave device by introducing a charge-to-spin converter that translates information from electrical domain to spin domain, magneto-electric spin wave repeaters that operate in three different regimes - spin wave transmitter, non-volatile memory and spin wave detector, and a novel clocking scheme that ensures sequential transmission of information and non-reciprocity. The proposed device satisfies the five essential requirements for logic application: nonlinearity, amplification, concatenability, feedback prevention, and complete set of Boolean operations.

Highlights

In this paper, we propose a comprehensive scheme for information transmission via spin waves
While similar approach to use a meta-stable magnetization state for spin wave detection has been suggested in a simplistic way in[23], ours is the first to take into consideration the essential characteristics like non-reciprocity and concatenability missing in the previous works and requires a carefully designed clocking scheme
As will be discussed later, the appropriate choice of the clock period results in the device acting as a buffer (PASS gate) or an inverter (NOT gate). This serves as a building block for designing majority gates and other logic gates, providing a complete set of Boolean operations

Summary

Introduction

We propose a comprehensive scheme for information transmission via spin waves. While similar approach to use a meta-stable magnetization state for spin wave detection has been suggested in a simplistic way in[23], ours is the first to take into consideration the essential characteristics like non-reciprocity and concatenability missing in the previous works and requires a carefully designed clocking scheme. We use the 90° switching of magnetization from a stable in-plane to a meta-stable out-of-plane state via ME effect to create new spin waves for transmitting signal to the stage This mechanism ensures an automatic amplification of spin wave signal at the end of each stage. As will be discussed later, the appropriate choice of the clock period results in the device acting as a buffer (PASS gate) or an inverter (NOT gate) This serves as a building block for designing majority gates and other logic gates, providing a complete set of Boolean operations. The clocking scheme of the ME cells designed for sequential transmission of information is comparable to the n-phase clocking technique used in CCD to encourage the charge packets to move cell to cell in a bucket-brigade style

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Conclusion