Auxiliary Mode Mediated Coherent and Complex Couplings in a Cavity Magnonic System

Abstract

AbstractCoherent and dissipative couplings are discovered in hybrid systems, which are frequently shown as the level repulsion and level attraction between the coupled modes, respectively. The coherent coupling can come from the direct dipole–dipole interaction or resonance‐mediated virtual photon exchange. The dissipative coupling originates from the bath‐induced cooperative damping effect. The interplay between these two couplings gives rise to complex coupling, contributing to novel phenomena and applications. In this work, it is studied how coherent and complex couplings can be readily realized and manipulated in a three‐mode cavity magnonic system. The three‐mode system consists of a two‐port cavity, a yttrium iron garnet (YIG) sphere (magnon mode), and a split‐ring resonator (auxiliary mode). A tunable split‐ring resonator mediates the coupling between the cavity mode and magnon mode. The coupling effect is theoretically analyzed by solving the steady‐state equation combined with numerical simulation. By adjusting several system parameters, the coherent and complex couplings mediated by the auxiliary mode are revealed. The study paves the way toward exploiting resonance‐ and dissipation‐induced couplings in hybrid systems.