Spontaneous creation and annihilation dynamics of magnetic skyrmions at elevated temperature

Abstract

Skyrmions are topologically protected nanoscale magnetic structures with a wide range of potential applications. Here we determine the life cycle of skyrmions from their creation to their intrinsic dynamics and thermal stability to their eventual thermodynamic demise. Using atomistic simulations of Ir/Co/Pt, parameterized from ab initio calculations, we demonstrate the thermal phase transition to a skyrmion state under application of a perpendicular magnetic field. The created skyrmions exhibit Brownian particlelike dynamics driven by the underlying thermal spin fluctuations. At an elevated temperature window well below the Curie temperature, the skyrmions are metastable and can collapse to a uniform magnetic state. With application of an external magnetic field, the intrinsic local thermal spin fluctuations at this elevated temperature window are sufficiently large to allow the spontaneous formation of new skyrmions in thermodynamic equilibrium analogous to a spontaneous skyrmion gas. Such a system could be used to implement a skyrmion-based true random number generator.

Device geometry dependent deterministic skyrmion generation from a skyrmionium

“…Also we have investigated the effect of current density to get different states of skyrmion in a single FM layer as well as in a SAF. The effect of temperature plays a crucial role in manipulating the nucleation and motion of these topological textures [57,58]. In this context, we have also performed the simulations at room temperature (at 300 K) which shows a good agreement with the results of simulations at 0 K. The obtained results are interesting for interdisciplinary research on skyrmion-based neuromorphic and unconventional computing.…”

Strain-induced magnetic phase transition, magnetic anisotropy switching and bilayer antiferromagnetic skyrmions in van der Waals magnet CrTe2

“…Protected by topology, skyrmions are more stable than traditional magnetic media and can exist stably even at the nanometer scale. [17][18][19][20][21] However, there exists an obstacle for the applications of skyrmions which is known as the skyrmion Hall effect (SkHE) [22][23][24] induced by the magnus force. In contrast, the SkHE of skyrmions in an antiferromagnetically exchange-coupled bilayer system is suppressed due to the cancelled magnus forces in the top and bottom layers.…”

Influence of magnetic structure on the performance of twisted skyrmion-based nano-oscillator

“…On account of some special features: stable small size [3][4][5], rigid shape [6,7], and the simplicity to be driven by ultra-low current density [8][9][10], magnetic skyrmion has now been widely studied. The generation and annihilation of skyrmion in ferromagnetic and antiferromagnetic materials is also a hot research topic [11][12][13][14]. In addition to current driven skyrmion [15], many methods * Author to whom any correspondence should be addressed.…”