Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Bond order wave (BOW) phase of the extended Hubbard model: Electronic
  solitons, paramagnetism, coupling to Peierls and Holstein phonons   The bond order wave (BOW) phase of the extended Hubbard model (EHM) in one
dimension (1D) is characterized at intermediate correlation $U = 4t$ by exact
treatment of $N$-site systems. Linear coupling to lattice (Peierls) phonons and
molecular (Holstein) vibrations are treated in the adiabatic approximation. The
molar magnetic susceptibility $\chi_M(T)$ is obtained directly up to $N = 10$.
The goal is to find the consequences of a doubly degenerate ground state (gs)
and finite magnetic gap $E_m$ in a regular array. Degenerate gs with broken
inversion symmetry are constructed for finite $N$ for a range of $V$ near the
charge density wave (CDW) boundary at $V \approx 2.18t$ where $E_m \approx
0.5t$ is large. The electronic amplitude $B(V)$ of the BOW in the regular array
is shown to mimic a tight-binding band with small effective dimerization
$\delta_{eff}$. Electronic spin and charge solitons are elementary excitations
of the BOW phase and also resemble topological solitons with small
$\delta_{eff}$. Strong infrared intensity of coupled molecular vibrations in
dimerized 1D systems is shown to extend to the regular BOW phase, while its
temperature dependence is related to spin solitons. The Peierls instability to
dimerization has novel aspects for degenerate gs and substantial $E_m$ that
suppresses thermal excitations. Finite $E_m$ implies exponentially small
$\chi_M(T)$ at low temperature followed by an almost linear increase with $T$.
The EHM with $U = 4t$ is representative of intermediate correlations in
quasi-1D systems such as conjugated polymers or organic ion-radical and
charge-transfer salts. The vibronic and thermal properties of correlated models
with BOW phases are needed to identify possible physical realizations.

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The categories of this paper are: solv-int
2
The categories of this paper are: math
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The categories of this paper are: q-alg
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The categories of this paper are: physics
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The categories of this paper are: acc-phys
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The categories of this paper are: chem-ph
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The categories of this paper are: adap-org
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The categories of this paper are: eess
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The categories of this paper are: stat
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The categories of this paper are: cs
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The categories of this paper are: comp-gas
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The categories of this paper are: mtrl-th
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-ex
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The categories of this paper are: gr-qc
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The categories of this paper are: alg-geom