C3: Dynamically driven quantum correlations
Hans Hübl, Christian Pfleiderer, Marc Wilde
The properties of quantum materials far from equilibrium will be studied by means of a multi-stimulus scheme, in which low-lying excitations are driven by means of intense microwave radiation while monitoring the response with a second probe. The approach aims to (i) identify the coupling of spin, orbital, lattice, or nuclear degrees of freedom under intense resonant microwave radiation, (ii) achieve tailored driving of quantum excitations such as topological magnons, orbitons, or electronic topological quasiparticles, (iii) create non-thermal melting of long-range order by intense microwave radiation, and (iv) realize the formation of dynamical forms of quantum order in bulk materials such as time crystals or many-body-localization.
Publications
2024 |
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Müller, M.; Weber, J.; Engelhardt, F.; Bittencourt, V. A. S. V.; Luschmann, T.; Cherkasskii, M.; Opel, M.; Goennenwein, S. T. B.; Kusminskiy, S. V.; Geprägs, S.; Gross, R.; Althammer, M.; Huebl, H. Chiral phonons and phononic birefringence in ferromagnetic metal–bulk acoustic resonator hybrids Journal Article Phys. Rev. B 109, 024430, 2024. @article{muller_chiral_2024, Magnomechanical devices, in which magnetic excitations couple to mechanical vibrations, have been discussed as efficient and broadband microwave signal transducers in the classical and quantum limit. We experimentally investigate the resonant magnetoelastic coupling between the ferromagnetic resonance modes in metallic Co25Fe75 thin films, featuring ultralow magnetic damping as well as sizable magnetostriction, and standing transverse elastic phonon modes in sapphire, silicon, and gadolinium gallium garnet at cryogenic temperatures. For all substrates, we observe a coherent interaction between the acoustic and magnetic modes. We identify the phonon modes as transverse shear waves propagating with slightly different velocities (Δv/v≃10−5); i.e., all investigated substrates show potential for phononic birefringence as well as phonon-mediated angular momentum transport. Our magnon-phonon hybrid systems operate in a coupling regime analogous to the Purcell enhanced damping in cavity magnonics. | |
2023 |
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Müller, M.; Weber, J.; Goennenwein, S. T. B.; Kusminskiy, S. V.; Gross, R.; Althammer, M.; Huebl, H. Temperature dependence of the magnon-phonon interaction in high overtone bulk acoustic resonator-ferromagnetic thin film hybrids Journal Article Phy. Rev. Applied 21, 034032, 2023. @article{muller_temperature_2023, |