Spin-wave control using dark modes in chiral magnonic resonators

We modeled, both analytically and numerically, the magnitude and phase of spin waves propagating in thin magnetic films and scattered from mesoscale chiral magnonic resonators. Our calculations reveal a remarkably strong chiral scattering of propagating spin waves from magnon dark modes hosted by the resonator, exceeding in strength the scattering from its quasiuniform mode. We formulate conditions for the waveguide-resonator system to be used as an efficient spin-wave diode and as a phase shifter. Both these applications are found to be feasible when using the available ferromagnetic materials for the resonators.