The Nanomagnetism Group is conducting basic and applied world-class research in the field of magnetism in nanoscale structures. The group staff has a long-standing expertise and proven track record in fundamental and applied aspects of nanomagnetism, magnetic materials, and magnetic characterization, especially magneto-optical methods. - MULTILAYER STRUCTURE DESIGN WITH TUNABLE MAGNETIC PROPERTIES: Magnetic thin films and the associated device components, such as the ones currently being employed in hard-drive disks (HDD) or MRAM memories, require magnetic materials with widely tunable properties to facilitate disruptive and novel technologies. In our work, we have demonstrated how novel materials design on the nm length-scale can manipulate magnetic phase transitions. Specifically, we design and fabricate single-crystal CoRu alloy films with gradual changes in their Ru concentration. Such predefined gradual changes allow for controlling the occurrence of the second-order phase transition of ferromagnets at the Curie temperature Tc. Similar materials design can be used to control multiple aspects of magnetic thin films, such as the thermodynamic critical exponents or their magnetization reversal and its temperature dependence. - MAGNETO-OPTICAL KERR EFFECT (MOKE) ELLIPSOMETRY TECHNIQUES: Quantifying the magnetization behaviors of magnetic materials can be a challenging task, given that they typically require the use of expensive tools or large facilities. In our work, we address this challenge with the use of the magneto-optical Kerr effect (MOKE). When light is reflected from a magnetic surface or thin film, the properties of the reflected light change with the magnetization vector. This, in turn, implies that we can determine the full magnetization vector orientation by just quantifying the relative changes in the reflected light. This MOKE based ellipsometry allows then for a cost-effective quantification of the magnetization behavior, using otherwise simple optical components, while achieving unprecedented precision. - LIGHT-CONTROLLED NANOMAGNETIC COMPUTATION: Nanomagnetic logics is a computational technology combining data storage and processing using magnetic phenomena. Advantages are nonvolatility, low power dissipation, and CMOS compatibility. Plasmon-assisted ns-pulsed photo-heating can be used to thermally activate the magnetic switching of selected nanostructures, based on wavelength and polarization of light. In the example above, this property is utilized to magnetically activate the output element of a simple nanomagnetic network implementing a reconfigurable, fast, and energy efficient Or/And nanomagnetic logic gate. - MAGNETO-PLASMONIC METAMATERIALS: Collective oscillation of free-like electrons of a metallic nanostructure induced by resonant coupling with the electromagnetic radiation, namely a localized surface plasmon polariton, excited in hybrid structures , named magneto-plasmonic nanostructures, comprising noble metals and magneto-optical active ferromagnetic metals allows for the active tuning of light polarization via an external magnetic stimulus. The active tuning is further enhanced by arranging the magneto-plasmonic nanostructures in a specific motif on a dielectric substrate, thereby realizing a so-called magneto-plasmonic metamaterial or crystal. Magneto-plasmonic metamaterials have potential applications in nanophotonics and ultra-sensitive biosensing.