Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Comprehensive Microscopic Theory for Coupling of
  Longitudinal--Transverse Fields and Individual--Collective Excitations   A plasmon is a collective excitation of electrons due to the Coulomb
interaction. Both plasmons and single-particle excitations (SPEs) are
eigenstates of bulk metallic systems and they are orthogonal to each other.
However, in non-translationally symmetric systems such as nanostructures,
plasmons and SPEs coherently interact. It has been well discussed that the
plasmons and SPEs, respectively, can couple with transverse (T) electric field
in such systems, and also that they are coupled with each other via
longitudinal (L) field. However, there has been a missing link in the previous
studies: the coherent coupling between the plasmons and SPEs mediated by the T
field. Herein, we develop a theoretical framework to describe the
self-consistent relationship between plasmons and SPEs through both the L and T
fields. The excitations are described in terms of the charge and current
densities in a constitutive equation with a nonlocal susceptibility, where the
densities include the L and T components. The electromagnetic fields
originating from the densities are described in terms of the Green's function
in the Maxwell equations. The T field is generated from both densities, whereas
the L component is attributed to the charge density only. We introduce a
four-vector representation incorporating the vector and scalar potentials in
the Coulomb gauge, in which the T and L fields are separated explicitly. The
eigenvalues of the matrix for the self-consistent equations appear as the poles
of the system excitations. The developed formulation enables to approach
unknown mechanisms for enhancement of the coherent coupling between plasmons
and the hot carriers generated by radiative fields.

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The categories of this paper are: nlin
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The categories of this paper are: supr-con
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The categories of this paper are: solv-int
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The categories of this paper are: bayes-an
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The categories of this paper are: quant-ph
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The categories of this paper are: math-ph
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The categories of this paper are: funct-an
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The categories of this paper are: alg-geom
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The categories of this paper are: astro-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: chem-ph
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The categories of this paper are: stat
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The categories of this paper are: q-alg
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The categories of this paper are: plasm-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: mtrl-th