Phase Diagram of a Single Skyrmion in Magnetic Nanowires

We investigate skyrmion phase diagrams in magnetic nanostructures numerically. We compare phase diagrams of nanowires and nanosquares, and find that nanowires have narrower single skyrmion phase than nanosquares, caused by difference in the confinement effect. Our results show that higher perpendicular anisotropy, higher Dzyaloshinskii-Moriya interaction, and lower saturation magnetization are required for a stable single skyrmion. From the current-driven skyrmion motion, a larger skyrmion moves faster, and is more stable against unwanted annihilation of skyrmion at wire edges.