Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A model for coupled $4f-3d$ magnetic spectra: a neutron scattering study
  of the Yb$-$Fe hybridisation in Yb$_3$Fe$_5$O$_{12}$   In this work, we explore experimentally and theoretically the spectrum of
magnetic excitations of the Fe$^{3+}$ and Yb$^{3+}$ ions in ytterbium iron
garnet (Yb$_3$Fe$_5$O$_{12}$). We present a complete description of the
crystal-field splitting of the $4f$ states of Yb$^{3+}$, including the effect
of the exchange field generated by the magnetically ordered Fe subsystem. We
also consider a further effect of the Fe-Yb exchange interaction, which is to
hybridise the Yb crystal field excitations with the Fe spin-wave modes at
positions in the Brillouin zone where the two types of excitations cross. We
present detailed measurements of these hybridised excitations, and propose a
framework which can be used in the quantitative analysis of the coupled spectra
in terms of the anisotropic $4f-3d$ exchange interaction.

13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th