Conceptual design of magnonic majority-logic gate based on channeling of spin waves in domain walls

Abstract

A three-input majority gate, which operates on the basis of majority decisions, can function as multifunctional Boolean logic gates. Here, we report a micromagnetic simulation study of a specially devised magnonic majority-logic gate that utilizes channeling of spin waves into narrow domain walls. Our model system is a four-armed cross structure where low-energy spin waves are guided and channeled along Néel-type domain walls and then interact with a single magnetic vortex positioned at the cross-point. After exciting spin waves simultaneously from the ends of three individual arms where input binary digits are encoded using spin-wave phase information, the phases of spin waves passing through the cross-point (after being scattered from the vortex) are measured as output binary digits at the end of the remaining single output arm. Consequently, the majority of the input variables determines the output signal, which is a clear sign of a majority gate. Furthermore, by setting a control input, our proposed single structure can perform multiple operations of AND-, OR-, NAND-, and NOR-gates. Finally, the gate structure and channeling spin waves into domain walls/their interaction with a vortex core have the additional merits of being free of the Joule heating typically encountered in conventional electronic devices and of having long coherence lengths.