Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Hubbard model on the triangular lattice: Spiral order and spin
  liquid   We investigate the half-filled Hubbard model on an isotropic triangular
lattice with the variational cluster approximation. By decreasing the on-site
repulsion $U$ (or equivalently increasing pressure) we go from a phase with
long range, three-sublattice, spiral magnetic order, to a non-magnetic Mott
insulating phase -- a spin liquid -- and then, for $U\lesssim6.7t$, to a
metallic phase. Clusters of sizes 3, 6 and 15 with open boundary conditions are
used in these calculations, and an extrapolation to infinite size is argued to
lead to a disordered phase at $U=8t$, but to a spiral order at $U\gtrsim 12$.

33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph