Volume 87, Number 6, September 2009
Article Number 67001
Number of page(s) 5
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 01 October 2009
EPL, 87 (2009) 67001
DOI: 10.1209/0295-5075/87/67001

Novel laser-induced dynamics in exchange-biased systems

A. Porat1, S. Bar-Ad1 and I. K. Schuller2

1   School of Physics and Astronomy, Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel
2   Physics Department, University of California, San Diego - La Jolla, CA 92093-0319, USA

received 26 May 2009; accepted in final form 4 September 2009; published September 2009
published online 1 October 2009

Ultrafast optical excitation of a ferromagnet/antiferromagnet (Ni/FeF2) exchange bias bilayer produces novel magnetization dynamics unlike ever observed before. An unexpected precession of the magnetization, in reverse magnetic fields that exceed the exchange bias, originates from a reorientation of frustrated spins at the interface. As the laser-excited interface approaches the blocking temperature, an exchange bias reversal can also be induced with a single excitation pulse, showing that not only the ferromagnet but also the antiferromagnet is strongly affected by the optical perturbation. This non-trivial response cannot be extrapolated from the known slow dynamics of magnetic bilayers, and provides important information on the physics of the interlayer coupling.

75.70.Cn - Magnetic properties of interfaces (multilayers, superlattices, heterostructures).
75.30.Gw - Magnetic anisotropy.
78.47.jc - Time resolved spectroscopy ( > 1 psec).

© EPLA 2009