Zusammenfassung
This work considers an Ising model on the Apollonian network, where the
exchange constant J(i,j)similar to 1/(k(i)k(j))(mu) between two
neighboring spins (i,j) is a function of the degree k of both spins.
Using the exact geometrical construction rule for the network, the
thermodynamical and magnetic properties are evaluated by iterating a
system of discrete maps that allows for very precise results in the
thermodynamic limit. The results can be compared to the predictions of a
general framework for spin models on scale-free networks, where the node
distribution P(k)similar to k(-gamma), with node-dependent interacting
constants. We observe that, by increasing mu, the critical behavior of the model changes from a phase transition at T=infinity for a uniform system (mu=0) to a T=0 phase transition when mu=1: in the thermodynamic
limit, the system shows no true critical behavior at a finite temperature for the whole mu >= 0 interval. The magnetization and
magnetic susceptibility are found to present noncritical scaling
properties.
Nutzer