dr. Alexej Kimel: Femtosecond opto-magnetism: Controlling and Harnessing the Fundamental Forces in Magnets

The idea to change properties of media with the help of light has long intrigued people in physics and chemistry. Understanding the mechanisms leading to photo-induced magnetic phenomena is a particularly intriguing problem as the strongest perturbation in light-matter interaction - the effect of the electric field of light on electric charges - conserves the spin. In my talk I will discuss how to control spins in magnets with the help of femtosecond laser pulses [1,2]. It will be shown that the laser pulses can effectively manipulate spins via ultrafast effect on spin-orbit [2] and exchange interactions [3,4] in magnetic materials. The effects are truly non-dissipative being observed even if the laser pulse is not absorbed [4]. I will also discuss scenarios in which the strength of the opto-magnetic effects can be employed to achieve ever faster magnetic switching [5].

References:

[1] A. Kirilyuk, A. V. Kimel, and Th. Rasing, Rev. Mod. Phys. 82, 2731 (2010).

[2] A. V. Kimel et al, Nature 435, 655 (2005).

[2] R. Mikhaylovskiy et al (submitted).

[3] R. Subkhangulov et al, Scientific Reports 4, 4368 (2014).

[4] D. Bossini et al, Phys. Rev B 89, 060405(R) (2014).

[5] T.A. Ostler et al, Nature-Communications 3, 666 (2012).