External Bias Field Control of Domain Wall to Skyrmion Conversion in a Typically Designed Magnetic Nanotrack

Understanding the evolution and tunable control of skyrmion dynamics is crucial for the effective development of next-generation racetrack memory (RM) devices. In this study, we present the micromagnetic simulation demonstrating precise control of skyrmion motion in a magnetic nanotrack composed of two (three) narrow and wider nanochannels under the influence of spin transfer torque (STT) and an out-of-plane bias field. Our results reveal that out-of-plane magnetic field assists in the efficient conversion of domain wall (DW) pair to skyrmion and results in the achievement of uniform velocity for each skyrmion. Furthermore, a thorough analysis of individual and total energy (TE) terms during the DW pair-to-skyrmion conversion provides detailed insight into the role of the bias field in overcoming the pinning potential at the junction of the narrow and wide nanochannel. The ability to precisely control the skyrmion motion stabilized from a DW pair under the influence of an external bias field is of significant importance for developing skyrmion-based memory devices.