Regensburg 2010 – scientific programme
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MA: Fachverband Magnetismus
MA 22: Spin Dynamics / Spin Torque III
MA 22.12: Talk
Thursday, March 25, 2010, 12:30–12:45, H10
Numerical investigation of opto-magnetic switching — •Denise Hinzke1, Stefan Gerlach1, Thomas Ostler2, Roy W. Chantrell2, and Ulrich Nowak1 — 1Universität Konstanz, 78457 Konstanz — 2University of York, York YO10 5DD, U. K.
Ultrafast magnetisation dynamics has been extensively studied recently as a possibility to improve the storage density as well as the writing speed in magnetic data storage. It was demonstrated [1] that a 40 fs, circularly polarised laser pulse is able to reverse the magnetisation. One possible explanation is that the laser pulse acts as an equally short magnetic field pulse pointing along the direction of light caused by the so-called inverse Faraday effect [2].
We perform single macro-spin simulations [3] within the framework of the Landau-Lifshitz-Bloch equation recently derived by Garanin [4]. One of our findings consistent with experimental results is that field pulse durations as short as 250 fs can be sufficient to reverse the magnetisation [5]. Furthermore, we found that the magnetisation switching is via a linear pathway [6] without any precession.
[1] C. D. Stanciu et al., Phys. Rev. Lett. 99, 047601 (2007) [2] A. V. Kimel et al, Nature (London) 435, 655 (2005) [3] N. Kazantseva et al, Phys. Rev. B 77, 184428 (2009), [4] D. A. Garanin, Phys. Rev. B 55, 3050 (1997), [5] K. Vahaplar et al, Phys. Rev. Lett. 103, 117201 (2009) [6] N. Kazantseva et al, Europhys. Lett. 81, 27004 (2008)