GROUND STATES FOR LARGE SAMPLES OF TWO-DIMENSIONAL ISING SPIN GLASSES

1999 ◽  
Vol 10 (04) ◽  
pp. 667-675 ◽  
Author(s):  
R. G. PALMER ◽  
JOAN ADLER

We have developed a combinatoric matching method to find the exact groundstate energy for the 2-D Ising spin glass with the ± J distribution and equal numbers of positive and negative bonds. For the largest size (1800×1800 plaquettes of spins), we averaged results from 278 samples and for the smaller ones up to 374, 375 samples. We also studied the behavior of the distributions of computer time (CPU) and memory as functions of sample size. We present finite size scaling leading to a groundstate energy estimate of E∞=-1.40193±2 for the infinite system. We found that the memory scales as the square of sample length and that for a given size, the CPU time appears to have a skewed and high-tailed distribution.

2000 ◽  
Vol 11 (03) ◽  
pp. 589-592
Author(s):  
FRAUKE LIERS ◽  
MICHAEL JÜNGER

By an exact calculation of the ground states for the ±J Edwards–Anderson spin glass, one can extrapolate the ground state energy to infinite system sizes. We calculate the exact ground states for the three-dimensional spin glass with free boundaries for system sizes up to 10 and fit different finite-size functions. We cannot decide, only from the quality of the fit, which fitting function to choose. Relying on the literature values for the extrapolated energy, we find the finite-size corrections to vary as 1/L.


2009 ◽  
Vol 20 (09) ◽  
pp. 1411-1421
Author(s):  
A. P. YOUNG

Some recent progress in Monte Carlo simulations of spin glasses will be presented. The problem of slow dynamics at low temperatures is partially alleviated by use of the parallel tempering (replica exchange) method. A useful technique to check for equilibration (applicable only for a Gaussian distribution) will be discussed. It will be argued that a finite size scaling analysis of the scaled correlation length of the system is a good approach with which to investigate phase transitions in spin glasses. This method will be used to study two questions: (i) whether there is a phase transition in zero field in the Heisenberg spin glass in three dimensions, and (ii) whether there is phase transition in a magnetic field in an Ising spin glass, also in three dimensions.


2016 ◽  
Vol 93 (3) ◽  
Author(s):  
T. Aspelmeier ◽  
Helmut G. Katzgraber ◽  
Derek Larson ◽  
M. A. Moore ◽  
Matthew Wittmann ◽  
...  

1996 ◽  
Vol 07 (03) ◽  
pp. 327-335 ◽  
Author(s):  
A. P. YOUNG ◽  
N. KAWASHIMA

We have studied the three-dimensional Ising spin glass with a ± J distribution by Monte Carlo simulations. Using larger sizes and much better statistics than in earlier work, a finite size scaling analysis shows quite strong evidence for a finite transition temperature, Tc, with ordering below Tc. Our estimate of the transition temperature is rather lower than in earlier work, and the value of the correlation length exponent, ν, is somewhat higher. Because there may be (unknown) corrections to finite size scaling, we do not completely rule out the possibility that Tc = 0 or that Tc is finite but with no order below Tc. However, from our data, these possibilities seem less likely.


1999 ◽  
Vol 121-122 ◽  
pp. 180-182
Author(s):  
M. Palassini ◽  
S. Caracciolo

1995 ◽  
Vol 5 (3) ◽  
pp. 355-364 ◽  
Author(s):  
R. M.C. de Almeida ◽  
L. Bernadi ◽  
I. A. Campbell

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