Atomically engineered periodic nanomagnets for the generation and propagation of terahertz spin excitations

• Applicant: Privatdozent Dr. Khalil Zakeri Lori
• Subject Area: Experimental Condensed Matter Physics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 563610511

A promising alternative to overcome the problems associated with electrical losses in nanoelectronic devices is utilizing short-wavelength ultrafast terahertz (THz) magnons, the quanta of collective magnetic excitations, for information transfer and processing. The essential requirement for realization of such devices is the ability of an efficient excitation of propagating coherent THz magnons in magnonic nanostructures. THz magnons in planar structures, e.g., ultrathin films and multilayers with thicknesses down to an atomic layer, have already been investigated. However, the fundamental possibility of the excitation and tailoring the properties of THz magnons in laterally confined periodic magnetic structures remains hitherto unexplored. The main objective of this project is to examine such a possibility and provide guidelines for designing well-ordered periodic magnetic nanostripes capable of generation and transmission of THz magnons. To this end, we plan to design several types of epitaxial magnetic nanostripes made of 3d magnetic elements on the 5x1 reconstructed Ir(001) surface. We shall probe all the emergent THz magnon modes in such atomically engineered structures by means of spin-polarized high-resolution electron energy-loss spectroscopy. A careful investigation of the magnon properties, e.g., the magnon dispersion relation, lifetime, group and phase velocity, in combination with ab initio calculations, shall help to unravel the complex nature of THz spin dynamics in such atomically designed nanowaveguides. Our results shall pave the way for designing ultrafast magnon-based logic devices with operation frequencies in the THz regime.

• DFG Programme: Research Grants