A micromagnetic theory of skyrmion lifetime in ultrathin ferromagnetic films
Anne Bernand-Mantel, Cyrill B. Muratov, Valeriy Slastikov
Abstract
We use the continuum micromagnetic framework to derive the formulas for compact skyrmion lifetime due to thermal noise in ultrathin ferromagnetic films with relatively weak interfacial Dzyaloshinskii-Moriya interaction. In the absence of a saddle point connecting the skyrmion solution to the ferromagnetic state, we interpret the skyrmion collapse event as "capture by an absorber" at microscale. This yields an explicit Arrhenius collapse rate with both the barrier height and the prefactor as functions of all the material parameters, as well as the dynamical paths to collapse.
Topics & Concepts
SkyrmionFerromagnetismCondensed matter physicsMicromagneticsMicroscale chemistryArrhenius equationSaddle pointPhysicsSaddleThermalThermal fluctuationsCurie temperatureMaterials scienceClassical mechanicsQuantum mechanicsMagnetic fieldMagnetizationThermodynamicsKineticsGeometryMathematicsMathematical optimizationMathematics educationMagnetic properties of thin filmsMagnetic Properties and ApplicationsTheoretical and Computational Physics