Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Surface Incommensurate Structure in an Anisotropic Model with competing
  interactions on Semiinfinite Triangular Lattice   An anisotropic spin model on a triangular semiinfinite lattice with
ferromagnetic nearest-neighbour interactions and one antiferromagnetic
next-nearest-neighbour interaction is investigated by the cluster
transfer-matrix method. A phase diagram with <2> antiphase, ferromagnetic,
incommensurate, and disordered phase is obtained. The bulk uniaxial
incommensurate structure modulated in the direction of the competing
interactions is found between the <2> antiphase and the disordered phase. The
incommensurate structure near the surface with free and <2> boundary condition
is studied at different temperatures. Paramagnetic damping at the surface and
enhancement of the incommensurate structure in the subsurface region at high
temperatures and a new subsurface incommensurate structure modulated in two
directions at low temperatures are found.

29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an