# Skyrmions in coupled spin torque nano-oscillator structures

## TL;DR

This study uses micromagnetic simulations to explore how magnetic coupling influences skyrmion creation in coupled spin-torque nano-oscillators, revealing that inter-oscillator distance affects the required current for skyrmion formation.

## Contribution

It demonstrates the role of magnetic coupling in skyrmion creation within coupled STNOs and maps the phase diagram for various parameters affecting this process.

## Key findings

- Magnetic coupling significantly influences skyrmion creation thresholds.
- Skyrmions can be generated from single-domain states with current pulses.
- Inter-oscillator distance alters the current needed for skyrmion formation.

## Abstract

In the present work, using micromagnetic simulation, we show that the magnetic coupling effect plays a very important role in the process of creation of skyrmions in a coupled system of spin-torque nano-oscillators (STNO). First, we have determined the magnetic ground state in an isolated STNO for different values of perpendicular uniaxial anisotropy (PUA) and Dzyaloshinskii-Moriya interaction (DMI). Next, we have applied a perpendicular pulse polarized current density (J) and found that it is possible to create a metastable N\'eel skyrmion from a disk whose ground state is a single magnetic domain. From these results, we obtained a phase diagram of polarized current intensity vs. time of application of the current pulse, for different values of parameters such as PUA, DMI, and distance between the STNOs. Our results show that, depending on the separation distance between the STNOs, the current density required to create a skyrmion changes due to the magnetic interaction.