Welcome to the magnetism group!
We are dedicated to cutting-edge research in the field of magnonics and related areas combined with excellent teaching.
Magnonics is a subfield of spintronics, which addresses the utilization of the spin degree of freedom for applications in information and communication technologies. We study „magnetic waves“, which are spin waves and their quanta called magnons, and we address new fundamental phenomena and their potential for applications. A particular focus is on macroscopic quantum phenomena such as supercurrents and their utilization, as well as on the development of magnonic devices for the information technology.
Our research is embedded in the Collaborative Research Center 173 „Spin+X“ funded by the Deutsche Forschungsgemeinschaft, as well as by several national, European and international projects. We offer opportunities for qualification in the frames of student assistantships, bachelor, master diploma and PhD projects in an international environment.
Ringvorlesung given on 25.04.2024 provides an overview of the research activities of our group and possible topics for bachelor and master work. The slides can be found here.
We work closely with the Nanoscale Magnonic Hybrids Research Group, led by Philipp Pirro.
News
07-2024
Wir freuen uns auf den Schülerinnentag 2024! |
03-2024
| Congratulations to Franziska Kühn! On March 18, 2024, after her talk at the Spring Meeting of the German Physical Society (DPG), Franziska was awarded the "INNOMAG e.V. Diploma / Master Prize 2024.“ The prize was presented by the DPG Working Group Magnetism in recognition of her diploma work "Untersuchung von Magnongasen in mikroskopischen, thermischen Landschaften" ("Investigation of magnon gases in microscopic thermal landscapes"), which she performed in the AG Magnetismus of RPTU Kaiserslautern-Landau. Currently, Franziska is working in the AG Magnetismus on her PhD within project B04 of the Transregional Collaborative Research Center 173 "Spin+X“, focusing on the nonlinear dynamics of Bose-Einstein magnon condensates. |
02-2024
| Our article "Local temperature control of magnon frequency and direction of supercurrents in a magnon Bose–Einstein condensate" has been selected as a "Featured Article" and is displayed on the cover of Applied Physics Letters The creation of temperature variations in magnetization, and hence in the frequencies of the magnon spectrum in laser-heated regions of magnetic films, is an important method for studying Bose–Einstein condensation of magnons, magnon supercurrents, Bogoliubov waves, and similar phenomena. In our study, we demonstrate analytically, numerically, and experimentally that, in addition to the magnetization variations, it is necessary to consider the connected variations of the demagnetizing field. In the case of a heat-induced local minimum of the saturation magnetization, the combination of these two effects results in a local increase in the minimum frequency value of the magnon dispersion at which the Bose–Einstein condensate emerges. As a result, a magnon supercurrent directed away from the hot region is formed. |
02-2024
| Our article "Persistent magnetic coherence in magnets" has been published in Nature Materials When excited, the magnetization in a magnet precesses around the field on a timescale governed by viscous magnetization damping, after which any information carried by the initial actuation seems to be lost. This damping appears to be a fundamental bottleneck for the use of magnets in information processing. However, here we demonstrate the recall of the magnetization-precession phase after times that exceed the damping timescale by two orders of magnitude using dedicated two-colour microwave pump–probe experiments for an YIG microstructured film. Time-resolved magnetization state tomography confirms the persistent magnetic coherence by revealing a double-exponential decay of magnetization correlation. We attribute persistent magnetic coherence to a feedback effect, that is, coherent coupling of the uniform precession with long-lived excitations at the minima of the spin-wave dispersion relation. Our finding liberates magnetic systems from the strong damping in nanostructures that has limited their use in coherent information storage and processing. See Publication |
Recent Publications
Influence of buffer/protective layers on the structural and magnetic properties of SmCo films on Silicon
F. Maspero, O.V. Koplak, A. Plaza, B. Heinz, F. Kohl, P. Pirro, R. Bertacco
IEEE Trans. Magn. , 1-1 (2024)
Injection locking in DC-driven spintronic vortex oscillators via surface acoustic wave modulation
R. Moukhader, D. R. Rodrigues, A. Riveros, A. Koujok, G. Finocchio, P. Pirro, A. Hamadeh
J. Appl. Phys. 136, 183901 (2024)
Nanoscale magnonic networks
Q. Wang, G. Csaba, R. Verba, A. V. Chumak, and P. Pirro
Phys. Rev. Applied 21, 040503 (2024)
More Publications
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