W. Jezewski, Multifractal analysis of first-order phase transitions in an Ising system with four-spin interactions, PHYSICA A, 278(1-2), 2000, pp. 235-242
The multifractal formalism is applied for investigating probability measure
s of energy levels of an Ising model with four-spin interactions on finite-
size hexagonal lattices. The Holder exponent characterizing singularities o
f these measures is determined as a function of the temperature variable an
d the ratio of the strength of four-spin interactions to the strength of tw
o-spin couplings. It is shown that for the variable values at which the sys
tem reveals the existence of a precursor of the first-order phase transitio
n, the maximal Holder exponent, associated with the energy region of the mo
st concentrated probability measure, possesses a minimum. which is nondiffe
rentiable with respect to temperature. (C) 2000 Elsevier Science B.V. All r
ights reserved.