Abstract

Magnonics deals with the physical properties of spin waves and utilizes them for data processing. Nanomagnonics addresses the investigation of spin waves in magnetic nanostructures with a minimum size of a few hundred nanometers or less. In the first part of my talk, I will briefly discuss the theory of spin waves in nanoscale waveguide and present the experimental realization of a nanoscale magnonic directional coupler. I will present the method of inverse-design magnonics, in which any functionality can be specified first, and a feedback-based computational algorithm is used to obtain the device design. In the second part, I will present our recent work on deeply nonlinear spin waves, including: (1) exchange spin wave excitation, (2) bistability switches, (3) magnonic repeaters, (4) magnonic neurons, and (5) magnonic random number generators. 

References:

1. Q. Wang*, Roman Verba, Björn Heinz, Michael Schneider, Ondřej Wojewoda, Kristýna Davídková, Khrystyna Levchenko, Carsten Dubs, Norbert J. Mauser, Michal Urbánek, Philipp Pirro , Andrii V. Chumak, Deeply nonlinear excitation of self-normalized short spin waves, Sci. Adv. 11, eadg4609 (2023).

2. Q. Wang*, A. V. Chumak, and P. Pirro, Inverse-design magnonic devices, Nat. Commun. 12, 2636 (2021)

3. Q. Wang*, M. Kewenig, M. Schneider, R. Verba, F. Kohl, B. Heinz, M. Geilen, M. Mohseni, B. Lägel, F. Ciubotaru, C. Adelmann, C. Dubs, S. D. Cotofana, O. V. Dobrovolskiy, T. Brächer, P. Pirro, and A. V. Chumak, A magnonic directional coupler for integrated magnonic half- adders, Nat. Electron. 3, 765-774 (2020)

4. Q. Wang*, A. Hamadeh, R. Verba, V. Lomakin, M. Mohseni, B. Hillebrands, A. V. Chumak, and P. Pirro, A nonlinear magnonic nano-ring resonator, NPJ Comput. Mater. 6, 192 (2020)

5. Q. Wang, B. Heinz, R. Verba, M. Kewenig, P. Pirro, M. Schneider, T. Meyer, B. Lägel, C. Dubs, T. Brächer and A. V. Chumak, Spin pinning and spin-wave dispersion in nanoscopic ferromagnetic waveguides, Phys. Rev. Lett. 122, 247202 (2019)

6. Q. Wang, P. Pirro, R. Verba, A. Slavin, B. Hillebrands, and A. V. Chumak, Reconfigurable nano-scale spin-wave directional coupler, Sci. Adv. 4, e1701517 (2018)

7. M. Mohseni,Q. Wang, B. Heinz, M. Kewenig, M. Schneider, F. Kohl, B. Lägel, C. Dubs, A. V. Chumak, and P. Pirro, Controlling of nonlinear relaxation of quantized magnons in nano-devices, Phys. Rev. Lett. 126, 097202 (2021)

Biography

Qi Wang is currently a full professor at the School of Physics from the Huazhong University of Science and Technology, China, since March 2023. Dr. Wang received his PhD from the Faculty of Physics in 2019 at the University of Kaiserslautern, Germany. After receiving his PhD, Dr. Wang continued his research at the Faculty of Physics at the University of Vienna as a postdoctoral researcher to study linear and nonlinear spin waves at nanoscales and their application in magnonic integrated circuits. In 2024, Dr. Wang received the prestigious Early Career Award of the IEEE Magnetic Society for his pioneering theoretical and experimental studies of linear and nonlinear spin waves in sub-100 nm conduits.