Percolation in \pm J Ising lattices after removing frustration

E. E. VOGEL; S. CONTRERAS; NIETO F.; RAMIREZ PASTOR A. J,

PHYSICA A - STATISTICAL AND THEORETICAL PHYSICS

ELSEVIER SCIENCE BV

Año: 1998 vol. 257 p. 256 - 263

0378-4371

Ising lattices with $pm J$ exchange interactions (bonds) present frustration. We consider computer simulations on square lattices where half the bonds are ferromagnetic and the other half are antiferromagnetic. Lattices $4 imes 4$ through $10 imes 10$ are calculated finding ground state properties and forming the diluted lattice that remains after removing all bonds that frustrate in any of the ground states. For each size, 500 randomly determined samples were prepared. About 2/3 of these diluted lattices percolate, which is more than randomly formed lattices with the same bond content. Percolation curves for the diluted lattice are obtained. The percolation threshold is found to be about 0.4, which is less than 0.5, the percolation threshold for randomly formed lattices. Percolation curves are better defined for diluted lattices when the fractional content of bonds in the largest island is used as independent variable.