Shining Light on Magnetism: Controlled Magnetic Switching With Ultrafast Optical Pulses
The possibilities of manipulating magnetization without applied magnetic fields have attracted growing attention over the last two decades. The low-power manipulation of magnetization, preferably at ultra-short time scales, has become a fundamental challenge with implications for future magnetic information storage and memory technologies. I will discuss recent experiments on the optical manipulation of the magnetization of engineered materials and devices using 50-5000 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. This includes optical control of ferromagnetic films and granular recording media that potentially enable breakthroughs for numerous applications since they include 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 ferromagnetic materials and a pathway to ultrafast spintronics.