Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fermionic bound states on a one-dimensional lattice   We study bound states of two fermions with opposite spins in an extended
Hubbard chain. The particles interact when located both on a site or on
adjacent sites. We find three different types of bound states. Type U is
predominantly formed of basis states with both fermions on the same site, while
two states of type V originate from both fermions occupying neighbouring sites.
Type U, and one of the states from type V, are symmetric with respect to spin
flips. The remaining one from type V is antisymmetric. V-states are
characterized by a diverging localization length below some critical wave
number. All bound states become compact for wave numbers at the edge of the
Brilloin zone.

33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom