Skyrmion blinking from the conical phase

TL;DR

This paper investigates the ultrafast creation and annihilation (blinking) of skyrmions in helimagnets near phase boundaries, revealing mechanisms involving chiral bobber states and proposing applications in probabilistic computing.

Contribution

It provides the first detailed analysis of skyrmion blinking dynamics using spin-dynamics simulations and HTST, highlighting the role of chiral bobbers and potential for probabilistic computing.

Findings

Bl blinking occurs near the skyrmion-conical phase boundary.

Chiral bobber surface states facilitate blinking behavior.

Estimated blinking times depend on magnetic field and temperature.

Abstract

While the transition between skyrmionic and non-topological states has been widely explored as a bit operation for information transport and storage in spintronic devices, the ultrafast dynamics of such transitions remains challenging to observe and understand. Here, we utilize spin-dynamics simulations and harmonic transition state theory (HTST) to provide an in-depth analysis of the nucleation of skyrmionic states in helimagnets. We reveal a persistent blinking (creation-annihilation) phenomenon of these topological states under specific conditions near the phase boundary between skyrmion and conical states. Through a minimum-energy path analysis, we elucidate that this blinking behavior is favored by the formation of chiral bobber (CB) surface states and that the collapse of CBs differs from that of skyrmions in thin films due to their different oscillation modes. We further employ HTST to estimate the typical blinking time as a function of the applied magnetic field and temperature. Finally, we illustrate the practical use of skyrmion blinking for controlled probabilistic computing, exemplified by a skyrmion-based random-number generator.