2nd_dataset-Minimal radius of magnetic skyrmions: statics and dynamics

<p>In a broad range of applied magnetic fields and material parameters isolated magnetic skyrmions<br> condense into skyrmion lattices. While the geometry of isolated skyrmions and their lattice<br> counterparts strongly depend on field and Dzyaloshinski–Moriya interaction, this issue has not been<br> adequately addressed in previous studies. Meanwhile, this information is extremely important for<br> applications, because the skyrmion size and the interskyrmion distance have to be tuned for skyrmion<br> based memory and logic devices. In this investigation we elucidate the size and density-dependent<br> phase diagram showing traditional phases in field versus material parameters space by means of<br> Monte-Carlo simulations on a discrete lattice. The obtained diagram permits us to establish that, in<br> contrast to the continuum limit, skyrmions on a discrete lattice cannot be smaller than some critical<br> size and have a very specific shape. These minimal skyrmions correspond to the micromagnetic<br> configuration at the energy barrier between the ferromagnetic and the skyrmionic states.<br> Furthermore, we use atomistic Landau–Lifshitz–Gilbert simulations to study dynamics of the<br> skyrmion annihilation. It is shown that this procees consists of two stages: the continuous skyrmion<br> contraction and its discontinuous annihilation. The detailed analysis of this dynamical process is<br> given.</p>