Logic Adders Based on Magnetic Skyrmions

Due to some prominent characteristics, magnetic skyrmions are expected to become information-carrying bits in future-generation logic devices. Until now, logic adders based on magnetic skyrmions have been scarcely exploited. Practically, skyrmion annihilation due to defects or the skyrmion Hall effect usually leads to failed operation in related devices. Here, we propose current-controlled skyrmion-based logic adders, the structure of which is deliberately designed to leverage skyrmion-edge interaction, skyrmion Hall effect, and even skyrmion annihilation. In the first step, we conceptually construct a simple half-adder — the basic unit of logic operation — and numerically demonstrate its functionality. Furthermore, through micromagnetic simulations, we examine the possibility of assembling the half-adders in an appropriate order to build a full adder. The proposed skyrmion-based adders are structurally simpler, operationally faster, and energetically more efficient than their CMOS-based logic gates or skyrmion-based logic devices.