Condensed Matter Physics, 2014, vol. 17, No. 4, 44701
DOI:10.5488/CMP.17.44701           arXiv:1501.02895

Title: Longitudinal evolution of magnetization of ferromagnets following ultrafast demagnetization: role of finite size and shape of demagnetized region
  I.A. Yastremsky (Taras Shevchenko National University of Kyiv, 64 Volodymyrska St., 01601 Kyiv, Ukraine)

A dependence of a relaxation rate on the shape of the demagnetized region for a longitudinal evolution of total magnetization to its equilibrium value following the ultrafast demagnetization is demonstrated. This shape-dependence is caused by a motion of the wave front inside the demagnetized region. The contribution of the wave front for spherically symmetric shape of the demagnetized region is up to 3 times and for cylindrically symmetric shape up to 2 times stronger than for one dimensional demagnetized region. This effect can be observed after the demagnetization by a tightly focused femtosecond laser pulse.

Key words: ultrafast demagnetization, ferromagnets, femtosecond laser
PACS: 75.78.Jp, 78.47.J

Full text [pdf] << List of papers