Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Exact solution of a Kondo lattice model   An integrable Kondo lattice model, which describes a strongly correlated
electron host interacting with a spin-1/2 lattice, is proposed. It is found
that with the variations of the Kondo coupling J, the hole concentration n_h
and the magnetic field H, the system may fall into a variety of phases. The
phase boundaries of the ground state are determined exactly. The marginal
excitations and the quantum critical behavior at the phase boundaries are
discussed.

2
The categories of this paper are: math
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th