One- and two-magnon excitations in FeBr₂

Phonon anomalies in pyrochlore iridates studied by Raman spectroscopy

“…[44] Based on its appearance below T N , we rather assign this mode to a single-magnon excitation that becomes Raman-active by virtue of the strong SOC and consequent strong single-ion anisotropy in the iridates. The intensity of the mode is higher than in typical collinear antiferromagnets, [45] but comparable to the one for magnons in other non-collinear magnets such as the canted antiferromagnets FeBr 2 [46] and FeF 2 [47]. The energy of the mode for T ≪ T N is consistent with the zone-center gap of dispersive magnons recently observed by resonant inelastic x-ray scattering (RIXS).…”

Magnetic polaritons in metamagnet layered structures: Spectra and localization properties

“…The dielectric constant of this medium is ε A = 1.5. The approximate values of the exchange and anisotropy parameters are known from Raman scattering [11][12][13], and are given by: J = 5.07 cm −1 , H A = 7.34 cm −1 , γ M z i = 1.2 kG and γ M z j = 1.45 kG. For the B medium, we consider the non-magnetic material ZnF 2 , whose dielectric constant is ε B = 8.…”

Magnetooptic coupling coefficients for one- and two-magnon Raman scattering in rutile-structure antiferromagnets FeF2, MnF2, CoF2, and NiF2

“…One piece of information that so far has seldom been investigated is the intensity of the excitation, using information from both Stokes and anti-Stokes Raman scattering measurements. Light scattering intensities of magnetic excitations are governed by the so-called magnetooptic coupling coefficients [2][3][4], which have so far been explored for the ferrimagnet Y 3 Fe 5 O 12 (YIG) [5], in this case by Brillouin scattering, and the metamagnets FeCl 2 and FeBr 2 [6][7][8]. However, the most detailed studies to date have been performed on the classic rutile-structure antiferromagnets [2], and it is the results from these Raman scattering investigations for both one-magnon and two-magnon excitations that are reviewed below.…”