Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Competition between attractive and repulsive interactions in
  two-component Bose-Einstein condensates trapped in an optical lattice   We consider effects of inter-species attraction on two-component gap solitons
(GSs) in the binary BEC with intra-species repulsion, trapped in the
one-dimensional optical lattice (OL). Systematic simulations of the coupled
Gross-Pitaevskii equations (GPEs) corroborate an assumption that, because the
effective mass of GSs is negative, the inter-species attraction may
\emph{split} the two-component soliton. Two critical values, $\kappa_{1} $ and
$\kappa_{2}$, of the OL strength ($\kappa $) are identified. Two-species GSs
with fully overlapping wave functions are stable in strong lattices ($\kappa
>\kappa_{1}$). In an intermediate region, $\kappa_{1}>\kappa >\kappa_{2}$, the
soliton splits into a double-humped state with separated components. Finally,
in weak lattices ($\kappa <\kappa_{2}$%), the splitting generates a pair of
freely moving single-species GSs. We present and explain the dependence of
$\kappa_{1}$ and $\kappa_{2}$ on thenumber of atoms (total norm), and on the
relative strength of the competing inter-species attraction and intra-species
repulsion. The splitting of asymmetric solitons, with unequal norms of the two
species, is briefly considered too. It is found and explained that the
splitting threshold grows with the increase of the asymmetry.

30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
2
The categories of this paper are: math