Magnetic skyrmion: from fundamental physics to pioneering applications

Abstract

Skyrmionic devices exhibit energy-efficient and high-integration data storage and computing capabilities due to their small size, topological protection, and low drive current requirements. So, to realize these devices, an extensive study, from fundamental physics to practical applications, becomes essential. In this article, we present an exhaustive review of the advancements in understanding the fundamental physics behind magnetic skyrmions and the novel data storage and computing technologies based on them. We begin with an in-depth discussion of fundamental concepts such as topological protection, stability, statics, and dynamics essential for understanding skyrmions, henceforth the foundation of skyrmion technologies. For the realization of CMOS-compatible skyrmion functional devices, the writing and reading of the skyrmions are crucial. We discuss the developments in different writing schemes such as STT, SOT, and VCMA. The reading of skyrmions is predominantly achieved via two mechanisms: the magnetoresistive tunnel junction TMR effect and topological resistivity. So, a thorough investigation into the skyrmion Hall effect, topological properties, and emergent fields is also provided, concluding the discussion on skyrmion reading developments. Based on the writing and reading schemes, we discuss the applications of the skyrmions in conventional logic, unconventional logic, memory applications, and neuromorphic computing, including a model of a skyrmion-based SNN architecture achieving over 90% accuracy on MNIST and fashion-MNIST datasets. Furthermore, we outline the potential of skyrmion-hosting Majorana zero modes in emerging topological quantum computation and helicity-dependent skyrmion qubits.