Simulation of a two-dimensional dipolar system on a APE100/quadrics SIMD architecture

Journal Article · Sun Jun 01 04:00:00 EDT 1997 · International Journal of Modern Physics C

DOI:https://doi.org/10.1142/S0129183197000382· OSTI ID:535103

Bruno, A; Pisacane, F; Rosato, V ^[1]

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1. ENEA Ente per le Nuove Tecnologie, Rome (Italy); and others

The temperature behavior of a system of dipoles with long-range interactions has been simulated via a two-dimensional lattice Monte Carlo on a massively (SIMD) platform (Quadrics/APE100). Thermodynamic quantities have been evaluated in order to locate and to characterize the phase transition in absence of applied field. Emphasis is given to the code implementation on the SIMD architecture and to the relevant features which have been used to improve code capabilities and performances. The probability of simultaneous occurrence of at least k spanning clusters has been studied by Monte Carlo simulations on the 2D square lattice with free boundaries at the bond percolation threshold p{sub c} = {1/2}. It is found that the probability of k and more Incipient Spanning Clusters (ISC) have the values P(k > 1) {approx} 0.00658(3) and P(k > 2) {approx} 0.00000148(21) provided that the limit of these probabilities for infinite lattices exists. The probability P(k > 3) of more than three ISC could be estimated to be of the order of 10{sup -11} and is beyond the possibility to compute such a value by nowadays computers. So, it is impossible to check in simulations the Aizenman law for the probabilities when k {much_gt} 1. We have detected a single sample with four ISC in a total number of about 1010 samples investigated. The probability of this single event is 1/10 for that number of samples. The influence of boundary conditions is discussed in the last section.

• OSTI ID: 535103
• Journal Information: International Journal of Modern Physics C, Journal Name: International Journal of Modern Physics C Journal Issue: 3 Vol. 8; ISSN 0129-1831; ISSN IJMPEO
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
99 GENERAL AND MISCELLANEOUS
COMPUTERIZED SIMULATION
DIPOLES
HAMILTONIANS
MONTE CARLO METHOD
PARALLEL PROCESSING
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
TWO-DIMENSIONAL CALCULATIONS