Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the origin of the quantum-critical transition in the bilayer
  Heisenberg model   The bilayer Heisenberg antiferromagnet is known to exhibit a quantum-critical
transition at a particular value of the inter-layer coupling. Using a new type
of coherent state, appropriate to the special order parameter structure of the
bilayer, we map the problem onto the quantum non-linear sigma model. It is
found that the bare coupling constant diverges at the classical transition of
Chubukov and Morr, so that in any finite dimension the actual transition occurs
inside the ordered phase of the classical theory.

16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys