Shining light on magnetism: controlled magnetic switching with femto-second laser pulses
UC San Diego, Center of Magnetic Recording Research
The possibilities of manipulating magnetization without applied magnetic fields have attracted growing attention over the last fifteen years. The low-power manipulation of magnetization, preferably at ultra-short time scales, has become a fundamental challenge with implications for future magnetic information, memory and storage technologies. I will discuss recent experiments on the optical manipulation of the magnetization of engineered materials and devices using 100 fs optical pulses. We demonstrate that all optical switching can be observed in a broad range of materials and not limited to selected rare-earth transition-metal alloy films as had been previously observed. We observe all optical switching in a variety of engineered materials, including ferrimagnetic alloys, multilayers, heterostructures and rare-earth-free Co-Ir-based synthetic ferrimagnets  and most recently observe optical control of ferromagnetic films. The latter discovery can enable breakthroughs for numerous applications since it exploits materials that are currently used in magnetic data storage, memories and logic technologies. In addition, this materials study of all-optical switching offers valuable insight into the underlying mechanisms involved in optical control of magnetism.
This work is supported, in part, by the Advanced Storage Technology Consortium and the ONR MURI program and is in collaboration with M. Gottwald, C.-H. Lambert, R. Tolley, V. Uhlir, and Y. Fainman at UCSD, S. Alebrand, D. Steil, M. Cinchetti and M. Aeschlimann at University of Kaiserslautern, and M. Hehn, D. Lacour and S. Mangin at Université de Lorraine.
. Mangin et al., Nature Materials 13, 286–292, (2014).
Eric Fullerton is a Professor in the Departments of Electrical and Computer Engineering and NanoEngineering and is an Endowed Chair and Director of the Center of Magnetic Recording Research. He received his B.Sc. in Physics from Harvey Mudd College in 1984 and his Ph.D. in Physics from UC San Diego in 1991. Previous to joining UC San Diego he held research positions at Argonne National Laboratory, the IBM Almaden Research Center and Hitachi Global Storage Technologies. His current research focuses the synthesis and characterization of magnetic nanostructures, both as a probe of materials in reduced dimensions and for the development of novel magnetic storage technologies. He has co-authored 260 journal articles, been issued 51 US patents and is a Fellow of the American Physical Society and the IEEE.