Realization of the skyrmionic logic gates and diodes in the same racetrack with enhanced and modified edges

Abstract

Magnetic skyrmions are topological quasiparticles with nanoscale size and high mobility, which have potential applications in information storage and spintronic devices. Here, we computationally investigate the dynamics of isolated skyrmions in a ferromagnetic racetrack, where magnetic properties of the edges are enhanced and modified, forming a channel with lower magnetic anisotropy for skyrmion motion. It is found that the rectangular notch at the edge can have a pinning effect on the skyrmion and enrich the dynamics of the skyrmion. Based on the racetrack with modified edges and the notch, we design a racetrack that realizes the skyrmionic logic AND, OR, and NOT gates as well as the diode in the same magnetic racetrack. It is found that the driving current density could be much smaller than those used in previous designs of skyrmion-based logic gates. By slightly altering the shape of the racetrack, we also design the NAND and NOR gates. Finally, we study the feasibility of our design at finite temperatures. Our results may contribute to the design of nonvolatile spintronic devices with integrated multiple functions and ultra-low energy consumption.

Dynamic behavior of skyrmion collision: spiral and breath

“…where D is the DMI constant, which describes the strength of interfacial DMI. The material parameters used in the present work are obtained from literatures [21,[51][52][53][54], which are listed as follows, M s = 0.58 ×…”

Stacking-dependent nonreciprocal transport in magnetic skyrmions

“…I also show that interlayer antiferromagnetic exchange interaction is necessary to realize the ABC-stacking SkX by performing the simulated annealing for an effective spin model with the momentum-resolved interaction on a trilayer triangular lattice. The present results indicate that the stacking degree of freedom of the SkX is another important degree of freedom to control the nonreciprocal transport properties driven by the noncoplanar spin textures, which will be useful for other spin textures [57,58,59] and future spintronic applications based on skyrmions [60,61,62].…”

Magnetic skyrmions and domain walls for logical and neuromorphic computing

“…Magnetic skyrmions as topological information carriers have been widely explored for integration in emerging computing systems. Specifically, [22,30,[49][50][51][52] use skyrmions for memory, [53][54][55][56][57][58][59][60] use skyrmions for logic gates, and [61][62][63][64][65] use skyrmions for neuromorphic computing applications. This section focuses on skyrmion logic gates and the associated driving scheme, while the following section shifts the focus to skyrmions in neuromorphic computing systems.…”

“…Compared to microfluidic logic [79] or magnetic bubble logic [80,81], magnetic skyrmions demonstrate the potential of implementing such reversible computing systems in a scalable manner for compact and energy-efficient design. Researchers have proposed many designs and systems for skyrmion logic: [53,56,82] utilize skyrmion-DW conversions or interactions for logical operations; [54] nucleates skyrmions through MTJs then drives the skyrmions with the SHE; [57] switches logic gate functions through manipulating the driving current density, and [83] reconfigures the gate through voltage-controlled magnetic anisotropy (VCMA).…”