Magnetic dipolar modes in magnon-polariton condensates

Abstract

For dipole-carrying excitations observed in a high-quality resonator, strong-coupling modes can appear as composite bosons with the spontaneous formation of quantized vortices in the condensed phase of a polariton fluid. In this paper, we show that magnon-polaritons can be realized due to magnon condensation caused by magnetic dipole-dipole interaction. In a quasi-2D ferrite disk placed in a microwave cavity, one observes quantum confinement effects of magnetic-dipolar-mode (MDM) oscillations. These modes, characterized by energy eigenstates with rotational superflows and quantized vortices, are exhibited as spinor condensates. Along with the condensation of MDM magnons, electric dipole condensation is also observed. At the MDM resonances, transfer between angular momenta in the magnetic insulator and in the vacuum cavity, demonstrates generation of vortex flows with fixed handedness. The unique topological properties of the polariton are manifested by curved wavefronts and supperradiance effects in microwave structures. In an environment of scattering states of microwave waveguide, electromagnetic (EM) waves can carry topological phases of MDM resonances.