Mechanical Dynamics Around Higher-Order Exceptional Point in Magno-Optomechanics

Diverse exceptional points (EPs) are theoretically studied in an experimentally feasible magno-optomechanics consisting of an optomechanical subsystem coupled to a magnomechanical subsystem via physically direct contact. By adiabatically eliminating both the cavity and the Kittel mode, dissipative and parity-time symmetric exceptional points can be observed. When only the cavity mode is eliminated, a second (third)-order pseudo-Hermitian EP emerges for nondegenerate (degenerate) mechanical modes. The distinct dynamical behavior of two mechanical modes around these EPs are further studied. The proposal provides a promising way to engineer diverse EPs and quantify non-Hermitian phase transition with exceptional dynamical behavior in magno-optomechanics.