Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Elementary excitations probed by L-edge resonant inelastic x-ray
  scattering in systems with weak and intermediate electron correlations   We develop a formalism to calculate the L-edge resonant x-ray scattering
(RIXS) spectra from transition-metal compounds. Using a multi-orbital
tight-binding model, we derive useful formulas to calculate the spectra by
collecting up the ladder diagrams on the basis of the Keldysh scheme, without
relying on the fast collision approximation. They are feasible in the weak and
intermediate coupling regimes of itinerant electron systems, where the charge
and the magnetic excitations are mixed together. We examine the difference
between the present formulas and those of the fast collision approximation.
Finally, to demonstrate how our theory works, we employ the formulas to study
the RIXS spectra on a simple model, the single-orbital Hubbard model on the
square lattice at half-filling. The intensities originated from the magnon and
from the continuous states are obtained on the equal footing in the
antiferromagnetic ground state.

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The categories of this paper are: q-alg
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
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The categories of this paper are: chem-ph
6
The categories of this paper are: astro-ph
27
The categories of this paper are: comp-gas
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The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
1
The categories of this paper are: cs
14
The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
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The categories of this paper are: mtrl-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: solv-int
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The categories of this paper are: hep-lat