Magnon polaron formed by selectively coupled coherent magnon and phonon modes of a surface patterned ferromagnet
| Autor: | Dmitri R. Yakovlev, A. V. Scherbakov, Achim Nadzeyka, Manfred Bayer, Mu Wang, Alexander N. Poddubny, A. W. Rushforth, F. Godejohann, S. M. Kukhtaruk, Dmytro D. Yaremkevich, A. V. Akimov |
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| Rok vydání: | 2019 |
| Předmět: |
Phonon
Dephasing FOS: Physical sciences 02 engineering and technology Polaron 01 natural sciences Condensed Matter::Materials Science Condensed Matter::Superconductivity 0103 physical sciences Mesoscale and Nanoscale Physics (cond-mat.mes-hall) 010306 general physics Physics Condensed Matter - Materials Science Condensed matter physics Condensed Matter - Mesoscale and Nanoscale Physics Condensed Matter::Other Magnon Materials Science (cond-mat.mtrl-sci) Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology Ferromagnetism Femtosecond Coherent states Condensed Matter::Strongly Correlated Electrons 0210 nano-technology Excitation |
| DOI: | 10.48550/arxiv.1909.01886 |
| Popis: | Strong coupling between two quanta of different excitations leads to the formation of a hybridized state which paves a way for exploiting new degrees of freedom to control phenomena with high efficiency and precision. A magnon polaron is the hybridized state of a phonon and a magnon, the elementary quanta of lattice vibrations and spin waves in a magnetically-ordered material. A magnon polaron can be formed at the intersection of the magnon and phonon dispersions, where their frequencies coincide. The observation of magnon polarons in the time domain has remained extremely challenging because the weak interaction of magnons and phonons and their short lifetimes jeopardize the strong coupling required for the formation of a hybridized state. Here, we overcome these limitations by spatial matching of magnons and phonons in a metallic ferromagnet with a nanoscale periodic surface pattern. The spatial overlap of the selected phonon and magnon modes formed in the periodic ferromagnetic structure results in a high coupling strength which, in combination with their long lifetimes allows us to find clear evidence of an optically excited magnon polaron. We show that the symmetries of the localized magnon and phonon states play a crucial role in the magnon polaron formation and its manifestation in the optically excited magnetic transients. Comment: 18 pages, 4 figures + Supplementary materials (available through the corresponding link given in References) |
| Databáze: | OpenAIRE |
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