Theory of spin resonance in a chiral helimagnet

It is suggested that marked features of symmetry-breaking mechanism and elementary excitations in chiral helimagnet come up as visible effects in electron-spin-resonance (ESR) profile. Under the magnetic field applied parallel and perpendicular to the helical axis, elementary excitations are, respectively, described by the helimagnon associated with rotational symmetry breaking and the magnetic kink crystal phonon associated with translational symmetry breaking. We demonstrate how the ESR spectra distinguish these excitations.