Propagating Low-Energy 4f Paramagnons

The field of science investigating spin waves and their quanta magnons and utilizing them for data processing is known as magnonics. This field offers new and exciting opportunities beyond traditional electronic systems. The typical materials used to investigate magnons are the magnetically- ordered ferro- and anti-ferromagnets at extremely low temperatures. Above these temperatures, the magnetic order is lost but the exchange stiffness, responsible for the spontaneous magnetic ordering, although decreases, remains finite. This allows the electron system to form local or itinerant magnetic moments. This phenomenon permitted the observation of high-energy magnons in the paramagnets by inelastic neutron scattering. These magnons are called paramagnons. The international project ParaMagnonics aims at the experimental observation of propagating low-energy paramagnons. These have a whole range of advantages over ordinary magnons, including a novel toolbox for quantum magnonics. The projects techniques include low-temperature microwave and Brillouin Light Scattering spectroscopy to detect and characterize the paramagnons. Afterward, electrical measurements and spin-orbit torque phenomena will be utilized to understand the nature of the diffusive paramagnons spin transport as well as to excite and amplify them. This project is heavily centered in optimizing the knowledge and know-how of the different teams working in it. The primary researchers involved in the project are: Univ- Prof. Dr. Andrii Chumak, University of Vienna, Austria; a. Prof. Dr. Gunther Springholz and Univ.-Prof. Dr. Andreas Ney, Johannes Kepler Universität, Austria; and Prof. Dr. Sergei Demokritov, Westfälische Wilhelms-Universität, Germany.