Seminaria

Dnia 2023.01.10 (wtorek) o godzinie 13.15, odbędzie się w seminarium na którym prof. dr hab. Maciej Krawczyk zInstytutu Spintroniki i Informacji Kwantowej, Wydziału Fizyki, Uniwersytetu im. Adama Mickiewicza w Poznani wygłosi wykład:

„Natural magnonic crystals: thin ferromagnetic film with magnetization stripe domain structure”

 Serdecznie zapraszamy

Andrzej Maziewski

Jerzy Przeszowski

Natural magnonic crystals: thin ferromagnetic film with magnetization stripe domain structure
prof. dr hab. Maciej Krawczyk
Instytut Spintroniki i Informacji Kwantowej, Wydział Fizyki, Uniwersytet im. Adama Mickiewicza w Poznaniu

The formation of a regular structure is an intriguing process that can be realized by spontaneous breaking of translational symmetry and lead to the formation of crystals, i.e., natural periodic potential tailoring the collective dynamics in solids. On a larger scale, in a continuous medium, the breaking of translational symmetry can be initiated by the linear dynamics of the eigen-waves in the homogeneous state and, together with the change of the control parameter, lead to the formation of a periodic pattern. Such a process has been observed in hydrodynamic systems, such as thermal convection, diffusion in two-component systems, non-linear optics, chemical reactions, as well as in biological systems [1]. Similarly, in an uniformly magnetized thin ferromagnetic layer, as a result of reducing the magnetic field magnitude, regular magnetization stripe domains may appear [2]. On the other hand, a regular magnetization pattern may provide a periodic potential for spin waves and allow the formation of a magnonic band structure [3-4]. We show that a thin ferromagnetic film with periodic stripe domains can be treated as a natural magnonic crystal, useful for controlling spin waves, offering a wide spectrum of phenomena with interesting physics and potential applications [5].

The research leading to these results has received funding from the Polish National Science Centre project UMO-2020/37/B/ST3/03936.

References:
[1] M. C. Cross and P.C. Hohenberg, Pattern formation outside of equilibrium, Rev. Mod. Phys. 65, 851 (1993).
[2] M. Grassi, et al., Higgs and Goldstone spin-wave modes in striped magnetic texture, Phys. Rev. B 105, 094444 (2022).
[3] C. Banerjee, et al., Magnonic band structure in a Co/Pd stripe domain system investigated by Brillouin light scattering and micromagnetic simulations, Phys. Rev. B 96, 024421 (2017).
[4] K. Szulc, et al., Reconfigurable magnonic crystals based on imprinted magnetization textures in hard and soft dipolar-coupled bilayers, ACS Nano 16, 14168 (2022)
[5] N. Träger et al., Real-space observation of magnon interaction with driven space-time crystals, Phys. Rev. Lett. 126, 057201 (2021).