  This work discusses the rich phase diagram of non-trivial chiral spin
textures in confined ferromagnetic/heavy-metal (FM/HM) bilayer nanomagnets of
circular cross-section. These spin textures are realized as a minimum-energy
ground state during an external bias field sweep for a range of nanomagnet's
diameter (d). Our study, based on micromagnetic simulations, has revealed a
novel Hopfion-like state which can be stabilized for a wide range of diameters
and external magnetic fields. We explored the dynamical characteristics of this
novel Hopfion-like state under a transient magnetic field applied along the
plane's perpendicular direction. Simulation results have demonstrated the
excitation of nonreciprocal spin wave (SW) modes for this novel chiral state,
in contrast to other stabilized chiral states. These modes are characterized as
breathing and quantized radial modes, which also exhibit hybridization with
azimuthal modes. The resonant SW modes have been used to demonstrate the
switching from a Hopfion-like state to a skyrmion within a few nanoseconds of
SW excitation. Furthermore, we establish a correlation between the behavior of
excited SW modes as a function of external magnetic field strength and
underlying chiral spin texture states.
