Lifetime of skyrmions

28.02.2019

For decades, tuning energy barriers has been the main approach to develop information storage bits based on magnetic materials. It is common wisdom that the energy barrier should exceed the thermal energy by a factor of about 50 at room temperature to ensure reliable bit stability. In a study published in Physical Review B (Rapid Comm.) Skyrmion lifetime in ultrathin films Stephan von Malottki, Soumyajyoti Haldar, and Stefan Heinze in collaboration with Pavel Bessarab, who is staying for one year in the Heinze group with an Alexander von Humboldt fellowship, and Anna Delin (KTH Stockholm) reveal that this criterion does not hold for magnetic skyrmions. The attempt frequency - normally assumed to be constant - can change by orders of magnitude with skyrmion diameter and can become the decisive factor for skyrmion stability. This work opens new paths towards stabilizing sub-10 nm skyrmions at room temperature.