164 research outputs found
Dynamic Exchange Coupling between Magnets Mediated by Attenuating Elastic Waves
Coupling between spatially separated magnets can be mediated by excitations
such as photons and phonons, which can be characterized as coherent coupling
and dissipative coupling with real and imaginary coupling rate. We
theoretically predict the existence of dynamic exchange coupling in a closed
magneto-elastic system mediated by attenuating elastic waves and whose coupling
rate is complex in general, leading to alternating repulsive or attractive
spectrum depending on thickness of the elastic media. The presence of dynamic
exchange coupling and its competition with coherent coupling are numerically
verified according to the generalized Hooke's law in magneto-elastic systems.
The predicted mechanism provides a new strategy to synchronize precessing
magnets as well as other excitations over long distance and pave the way for
non-Hermitian engineering of collective modes in hybrid magnonics, phononics
and photonics.Comment: 12 pages, 6 figures (including supplemental materials
Circulating cavity magnon polaritons
We predict magnon-polariton states circulating unidirectionally in a microwave cavity when loaded by a number of magnets on special lines. Realistic finite-element numerical simulations, including dielectric, time-dependent, and nonlinear effects, confirm the validity of the approximations of a fully analytical input-output model. We find that a phased antenna array can focus all power into a coherent microwave beam with controlled direction and an intensity that scales with the number of magnets.</p
Circulating cavity magnon polaritons
We predict magnon polariton states circulating unidirectionally in a
microwave cavity when loaded by a number of magnets on special lines. Realistic
finite-element numerical simulations, including dielectric, time-dependent and
non-linear effects, confirm the validity of the approximations of a fully
analytical input-output model. We find that a phased antenna array can focus
all power into a coherent microwave beam with controlled direction and an
intensity that scales with the number of magnets.Comment: 12 pages, 6 figure
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