Seminaria

Seminarium wydziałowe

Dnia 2019-11-19 o godzinie 14:15 w sali 2011 Wydziału Fizyki UwB odbędzie się wykład, na którym dr Justyna Rychły z Instytutu Fizyki Molekularnej PAN w Poznaniuwygłosi wykład pt:

"Localization properties of spin waves in planar magnonic crystals and quasicrystals"

Serdecznie zapraszamy

Andrzej Maziewski

This seminar would be devoted to the localization of spin waves in magnonic crystals and quasicrystals, and SW dynamics in a single nanowire being the building block of these structures [1]. Quasicrystals are structures that exhibit long-range order, lack translational periodicity, but possess another noteworthy symmetry property, which is self-similarity by scaling [2]. Therefore, magnonic quasicrystals surpass regular magnonic crystals [3] regarding provided by them possibilities of spin waves control: they offer complex, self-similar spin wave spectra, localization of spin waves inside the structure, and on the surfaces of the structure [4,5]. The results of joint collaborative research with the experimental groups will be shown, demonstrating the possibility of spin wave propagation through magnonic quasicrystal, the opening of additional mini-bandgaps [6], and the reprogrammability of the resonance frequencies, dependent on the magnetization order in magnonic quasicrystals [7]. The measurements of SWs propagating in a 1D Fibonacci sequence of dipolarly coupled permalloy nanowires are done with the help of a combined X-ray microscopic and Brillouin Light Scattering. The experimental results are interpreted using numerical calculations. Additionally, a simple model estimating frequencies of magnonic gaps in the spin wave spectra of the Fibonacci quasiperiodic structure matches the frequency mini-band gaps calculated numerically and measured experimentally. The demonstrated features of one-dimensional magnonic quasicrystals allow utilizing this class of metamaterials for magnonics and make them an ideal basis for future applications.

[1] J. Rychły, V. S Tkachenko, J. W. Kłos, A. Kuchko, M. Krawczyk, Spin wave modes in a cylindrical nanowire in crossover dipolar-exchange regime, Journal of Physics D: Applied Physics, 52 075003 (2019) [2] C. Janot, Quasicrystals: A Primer 2nd edition, Oxford University Press, 2012 [3] Justyna Rychły, Jarosław W. Kłos, Spin wave surface states in 1D planar magnonic crystals, Journal of Physics D: Applied Physics, 50, 164004, (2017) [4] J. Rychły, J. W. Kłos, M. Mruczkiewicz, M. Krawczyk, Spin waves in one-dimensional bicomponent magnonic quasicrystals, Physical Review B 92, 054414 (2015) [5] J. Rychły, J. W. Kłos, and M. Krawczyk, Spin wave damping in periodic and quasiperiodic magnonic structures, Journal of Physics D: Applied Physics, 49, 175001 (2016) [6] Filip Lisiecki, Justyna Rychły, Piotr Kuświk, Hubert Głowiński, Jarosław W. Kłos, Felix Groß, Nick Träger, Iuliia Bykova, Markus Weigand, Mateusz Zelent, Eberhard J. Goering, Gisela Schütz, Maciej Krawczyk, Feliks Stobiecki, Janusz Dubowik, and Joachim Gräfe, Magnons in a Quasicrystal: Propagation, Extinction, and Localization of Spin Waves in Fibonacci Structures, Phys. Rev. Applied 11, 054061 (2019) [7] F. Lisiecki, J. Rychły, P. Kuświk, H. Głowiński, J. W. Kłos, F. Groß, I. Bykova, M. Weigand, M. Zelent, G. Schütz, G. Gubbiotti, M. Krawczyk, F. Stobiecki, J. Dubowik, and J. Gräfe, Reprogrammability and scalability of Fibonacci magnonic quasicrystal, Physical Review Applied 11, 054003 (2019)