1-Bit Full Adder in Perpendicular Nanomagnetic Logic using a Novel 5-Input Majority Gate

Stephan Breitkreutz,Michael Niemier,György Csaba,Doris Schmitt-Landsiedel,Josef Kiermaier,Adam Papp,Irina Eichwald,Markus Becherer,Wolfgang Porod,D Niarchos,G Hadjipanayis,O Kalogirou

doi:10.1051/epjconf/20147505001

Abstract

In this paper, we show that perpendicular Nanomagnetic Logic (pNML) is particularly suitable to realize threshold logic gate (TLG)-based circuits. Exemplarily, a 1-bit full adder circuit using a novel 5-input majority gate based on TLGs is experimentally demonstrated. The theory of pNML and its extension by TLGs is introduced, illustrating the great benefit of pNML. Majority gates based on coupling field superposition enable weighting each input by its geometry and distance to the output. Only 5 magnets, combined in two logic gates with a footprint of 1.95 μm 2 and powered by a perpendicular clocking field, are required for operation. MFM and magneto-optical measurements demonstrate the functionality of the fabricated structure. Experimental results substantiate the feasibility and the benefits of the combination of threshold logic with pNML.

Highlights

Nanomagnetic Logic (NML) is an emerging information processing technology using the interaction of bistable magnets to perfom logic operations [1, 2]
Perpendicular NML uses CoPt or CoNi nanomagnets with perpendicular magnetic anisotropy (PMA). It benefits from flexible geometries and shape independent anisotropy, which is tuned by focused ion beam (FIB) irradiation [5]
Majority gates offer the possibility to weight each input by its coupling field, which is defined by the inputs geometry and distance to the artificial nucleation centers (ANCs)

Summary

Introduction

Nanomagnetic Logic (NML) is an emerging information processing technology using the interaction of bistable magnets to perfom logic operations [1, 2]. Perpendicular NML (pNML) uses CoPt or CoNi nanomagnets with perpendicular magnetic anisotropy (PMA). It benefits from flexible geometries and shape independent anisotropy, which is tuned by focused ion beam (FIB) irradiation [5]. -called artificial nucleation centers (ANCs) are fabricated by partial FIB irradiation at user-defined positions and provide directed signal flow in chains [6,7,8] and gates [9] of field-coupled nanomagnets. Information is processed by complex circuits providing non-volatile logic operation using majority gates and inverters connected by wires [10]. We exemplary demonstrate a TLG-based full adder circuit using a novel 5-input majority gate by experiment

Theory of perpendicular NML

TLG-based pNML

Experiment

Findings

Conclusion