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

Abstract

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.

Characterization of the magnetization reversal of perpendicular Nanomagnetic Logic clocked in the ns-range

“…For pNML, a narrow distribution is preferred as it allows more reliable switching of the magnets and therefore leads to less error prone NML circuits and systems. 18 The observed behavior above 100 ns can be modeled with the well known Arrhenius equation 5 :…”

Modeling and simulation of nanomagnetic logic with cadence virtuoso using Verilog-A

“…The only difference to the pNML inverter is that the summation part of a model accepts more than one input beside the external clock. Depending on the logic gate configurations it can have up to 5 inputs [6]. All the incoming fields are weighted and added to the net field which is then provided to the ANC.…”

“…Majority gates, realized by the superposition of stray fields within arrays of magnets, provide basic logic operations, which can be assembled to complex logic circuits by interconnecting several gates with magnetic nanowires [4]. Recently presented devices, such as Domain Wall Gates [5] or 1-bit full adders [6], demonstrated by experiment have proven the feasibility of this technique. Moreover, NML with perpendicular anisotropy (pNML) is suitable for monolithic 3D integration of devices and circuits enabling ultra large scale integration [7,8].…”

Experiment-based thermal micromagnetic simulations of the magnetization reversal for ns-range clocked nanomagnetic logic

“…Fabricated and fully functional inverters, majority gates and a system based on interconnected basic devices was published in recent years. 4 E. g., the experimentally shown full adder requires just five nanomagnets 5 compared to several tens of transistors in CMOS technology. The 3D nature of stray magnetic fields also enables very dense 3D integration through stacking functional layers as shown experimentally for magnetic vias and a 3D majority gate.…”