Femtosecond Magneto-Optics and Opto-Magnetism

Femtosecond Magneto-Optics and Opto-Magnetism:

from fundamentals to the fastest ever magnetic recording

A. V. Kimel

Radboud University, Institute for Molecules and Materials, Nijmegen, The Netherlands

Moscow Technological University (MIREA), Moscow, The Netherlands

Although, the move to wireless devices and the increase of cloud storage ensures that in the 21st century’s digital economy the demands for denser, faster and more energy efficient data storage will keep growing even further, the heat produced by modern data centers is already a serious limitation to further increase their performance. Controlling the magnetic state of media with the lowest possible cost of energy and simultaneously at the fastest possible time-scale is a new and great challenge in fundamental magnetism. A femtosecond laser pulse excites magnets much faster than characteristic times of atomic, orbital, spin motion and steers magnetization dynamics along yet unexplored, non-thermodynamic routes [1]. Can light directly magnetize a medium? In my lecture I will discuss fundamental aspects of interaction between photons and spins, magneto-optical and opto-magnetic phenomena [2] as well as possible microscopical mechanisms for ultrafast laser control of magnetism [3,4]. Recent experiments on ultrafast and least dissipative all-optical magnetic recording in metallic alloys [5], multilayers [6,7] and dielectric garnet films [8] will be reviewed.

[1] A. Kirilyuk, A. V. Kimel, Th. Rasing, Ultrafast optical manipulation of magnetic order, Review of Modern Physics 82 2731-2784 (2010).

[2] A. V. Kimel, A. Kirilyuk, P. A. Usachev, R. V. Pisarev, A. M. Balbashov, and Th. Rasing, Ultrafast non-thermal control of magnetization by instantaneous photomagnetic pulses, Nature 435, 655 (2005).

[3] I. Radu, K. Vahaplar, C. Stamm, T. Kachel, N. Pontius, H. A. Durr, T. A. Ostler, J. Barker, R. F. L. Evans, R. W. Chantrell, A. Tsukamoto, A. Itoh, A. Kirilyuk, Th. Rasing, and A. V. Kimel, Transient ferromagnetic-like state mediating ultrafast reversal of antiferromagnetically coupled spins, Nature 472 205-208 (2011).

[4] T.A. Ostler et al, Ultrafast heating as a sufficient stimulus for magnetization reversal in a ferrimagnet, Nature-Communications 3, 666 (2012).

[5] C. D. Stanciu, F. Hansteen, A. V. Kimel, A. Kirilyuk, A. Tsukamoto, A. Itoh, and Th. Rasing, All-Optical Magnetic Recording with Circularly Polarized Light, Physical Review Letters 99, 047601 (2007).

[6] S. Mangin, M. Gottwald, C.H. Lambert, D. Steil, V. Uhlir, L. Pang, M. Hehn, S. Alebrand, M. Cinchetti, G. Malinowski, Y. Fainman, M. Aeschlimann, and E.E. Fullerton, Engineered materials for all-optical helicity-dependent magnetic switching, Nature Materials 13, 286–292 (2014).

[7] C.H. Lambert, S. Mangin, B. Varaprasad, Y.K. Takahashi, M. Hehn, M. Cinchetti, G. Malinowski, K. Hono, Y. Fainman, M. Aeschlimann, and E.E. Fullerton, All-optical control of ferromagnetic thin films and heterostructures, Science345, 1337 (2014).

[8] A. Stupakiewicz, K. Szerenos, D. Afanasiev, A. Kirilyuk, A. V. Kimel, Ultrafast photo-magnetic recording in transparent medium (submitted).