Optically-induced magnetization reversal of coupled zero moment ferrimagnets and synthetic ferrimagnets

• Applicants: Professor Dr. Manfred Albrecht; Dr. Helmut Schultheiß
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2014 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 260967153

The aim of the proposed research project is to explore the potential of all-optical switching as a novel approach to ultra-fast magnetization reversal important for future information processing technology. The insatiable demand for digital data storage is still the driving force for ever increasing areal density, larger capacities and better performance of hard disk drives. However, the speed of magnetic data storage and information processing is particularly important for device performance, but presently limited to a few nanoseconds. Thus the demand for increasing speed of information storage has triggered intense research activities for finding ways to control the magnetization at ultrashort time scales. In this regard, ultra-fast magnetization reversal processes induced by circular polarized femto¬second laser pulses was observed recently in ferrimagnetic rare earth-transition metal (RE-TM) alloy thin films, where the direction of the switching is determined by the helicity of the light in the absence of any external applied magnetic fields. However, many fundamental aspects of the underlying mechanism in all-optical switching are not yet understood, and additional experimental efforts are required to reveal the fundamental physics involved. This complex scientific challenge of all-optical switching is in the focus of the proposed research project including various novel material systems such as coupled ferrimagnetic heterostructures with zero net moment as well as synthetic ferrimagnets based on antiferromagnetically coupled ferromagnetic layers.

• DFG Programme: Research Grants