Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Thermodynamic properties of the SO(5) theory for the antiferromagnetism
  and d-wave superconductivity: a Monte Carlo study   The present approach takes into account thermal fluctuations both in the
rotation of SO(5) superspins between the AF and SC subspaces, and in the phase
variables of SC order parameters. Temperature vs. g-field phase diagrams for
null external magnetic field are presented, where the g field is conjugate with
the quadratic order parameters and breaks the SO(5) symmetry. The normal(N)/AF
and N/SC phase boundaries merge tangentially at the bicritical point into the
AF/SC phase boundary. Hysteresis phenomenon is observed at the AF/SC phase
transition. Enhancement of AF correlations is observed above the SC critical
temperature in systems with AF couplings stronger than SC ones. Its relation
with the spin-gap phenomenon is addressed. The SO(5) theory in an external
magnetic field is also investigated. At sufficiently large g fields the SC
order is established through a first-order freezing transition of the flux-line
lattice. Short-range AF fluctuations are larger at cores of flux lines than
elsewhere, and decrease continuously to zero with increasing g field. At
intermediate g fields, the flux-line lattice of long-range SC order and the
long-range AF order coexist. Superlattice spots surrounding the strong AF Bragg
peaks at Q=(\pm\pi,\pm\pi) are observed in the simulated structure factor, and
are identified with the modulation by the triangular flux-line lattice of SC.
The AF phase boundary associated with the continuous onset of long-range AF
order drops sharply to the g axis from a finite temperature in the temperature
vs. g-field phase diagram.

33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex