https://doi.org/10.1007/s100510050789
Frustrated Blume-Emery-Griffiths model
Service de Physique Théorique, CEA Saclay,
91191 Gif-sur-Yvette Cedex, France
Division de Physique Théorique, Institut de Physique
Nucléaire,
Université Paris-Sud, 91406 Orsay Cedex, France
Received:
13
January
1997
Published online: 15 June 1999
A generalised integer S Ising spin glass model is analysed
using the replica formalism. The bilinear couplings are
assumed to have a Gaussian distribution with ferromagnetic
mean 
. Incorporation of a quadrupolar
interaction term and a chemical potential leads to a richer
phase diagram with transitions of first and second order.
The first order transition may be interpreted as a phase
separation, and contrary to what has been argued previously,
it persists in the presence of disorder. Finally, the
stability of the replica symmetric solution with respect
to fluctuations in replica space is analysed, and the
transition lines are obtained both analytically and numerically.
PACS: 75.10.Nr – Spin-glass and other random models / 64.60.Cn – Order-disorder and statistical mechanics of model systems / 05.50.+q – Lattice theory and statistics (Ising, Potts, etc.)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999
