Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Band spectra of periodic hybrid $\delta$-$\delta^\prime$ structures   We present a detailed study of a generalised one-dimensional Kronig-Penney
model using $\delta\text{-}\delta'$ potentials. We analyse the band structure
and the density of states in two situations. In the first case we consider an
infinite array formed by identical $\delta\text{-}\delta'$ potentials standing
at the linear lattice nodes. This case will be known throughout the paper as
the one-species hybrid Dirac comb. We investigate the consequences of adding
the $\delta'$ interaction to the Dirac comb by comparing the band spectra and
the density of states of pure Dirac-$\delta$ combs and one-species hybrid Dirac
combs. Secondly we study the quantum system that arises when the periodic
potential is the one obtained from the superposition of two one-species hybrid
Dirac combs displaced one with respect to the other and with different
couplings. The latter will be known as the two-species hybrid Dirac comb. One
of the most remarkable results is the appearance of a curvature change in the
band spectrum when the $\delta'$ couplings are above a critical value.

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The categories of this paper are: astro-ph
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The categories of this paper are: cs
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The categories of this paper are: adap-org
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The categories of this paper are: q-fin
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The categories of this paper are: q-bio
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The categories of this paper are: solv-int
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The categories of this paper are: gr-qc
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The categories of this paper are: chao-dyn
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The categories of this paper are: funct-an
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The categories of this paper are: econ
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The categories of this paper are: supr-con
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The categories of this paper are: ao-sci
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The categories of this paper are: bayes-an
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-th
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The categories of this paper are: acc-phys