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Related papers: Lower Critical Dimension of Ising Spin Glasses

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We analyze exact ground-state energies of two-dimensional Ising spin glasses with either Gaussian or bimodal nearest-neighbor interactions for large system sizes and for three types of boundary conditions: free on both axes, periodic on…

Disordered Systems and Neural Networks · Physics 2007-05-23 I. A. Campbell , A. K. Hartmann , Helmut G. Katzgraber

We study large-scale, low-energy excitations in the Ising spin glass with Gaussian interactions in two-dimensions at zero temperature, using an optimization algorithm to determine exact ground states. Periodic boundary conditions are…

Disordered Systems and Neural Networks · Physics 2009-11-07 A. K. Hartmann , A. P. Young

Using mappings to computer-science problems and by applying sophisticated algorithms, one can study numerically many problems much better compared to applying standard approaches like Monte Carlo simulations. Here, using calculations of…

Disordered Systems and Neural Networks · Physics 2007-05-23 A. K. Hartmann

We compute the exact partition function of 2d Ising spin glasses with binary couplings. In these systems, the ground state is highly degenerate and is separated from the first excited state by a gap of size 4J. Nevertheless, we find that…

Disordered Systems and Neural Networks · Physics 2009-11-10 J. Lukic , A. Galluccio , E. Marinari , Olivier C. Martin , G. Rinaldi

The Ising spin glass in two dimensions exhibits rich behavior with subtle differences in the scaling for different coupling distributions. We use recently developed mappings to graph-theoretic problems together with highly efficient…

Disordered Systems and Neural Networks · Physics 2018-03-02 Hamid Khoshbakht , Martin Weigel

We study domain walls in 2d Ising spin glasses in terms of a minimum-weight path problem. Using this approach, large systems can be treated exactly. Our focus is on the fractal dimension $d_f$ of domain walls, which describes via $<\ell…

Disordered Systems and Neural Networks · Physics 2009-11-13 O. Melchert , A. K. Hartmann

With the help of EXACT ground states obtained by a polynomial algorithm we compute the domain wall energy at zero-temperature for the bond-random and the site-random Ising spin glass model in two dimensions. We find that in both models the…

Disordered Systems and Neural Networks · Physics 2009-10-28 N. Kawashima , H. Rieger

The critical behaviors of the bimodal and Gaussian Ising spin glass (ISG) models in dimension four are studied through extensive numerical simulations, and from an analysis of high temperature series expansion (HTSE) data of Klein {\it et…

Disordered Systems and Neural Networks · Physics 2015-07-09 P. H. Lundow , I. A. Campbell

We study the scaling behavior of domain-wall energies in two-dimensional Ising spin glasses with Gaussian and bimodal distributions of the interactions and different types of boundary conditions. The domain walls are generated by changing…

Disordered Systems and Neural Networks · Physics 2009-11-07 Alexander K. Hartmann , Alan J. Bray , A. C. Carter , M. A. Moore , A. P. Young

Ising spin glass models with bimodal, Gaussian, uniform and Laplacian interaction distributions in dimension five are studied through detailed numerical simulations. The data are analyzed in both the finite-size scaling regime and the…

Disordered Systems and Neural Networks · Physics 2017-01-18 P. H. Lundow , I. A. Campbell

We use transfer-matrix and finite-size scaling methods to investigate the location and properties of the multicritical point of two-dimensional Ising spin glasses on square, triangular and honeycomb lattices, with both binary and Gaussian…

Statistical Mechanics · Physics 2009-05-21 S. L. A. de Queiroz

We study how the ground state of the two-dimensional Ising spin glass with Gaussian interactions in zero magnetic field changes on altering the boundary conditions. The probability that relative spin orientations change in a region far from…

Disordered Systems and Neural Networks · Physics 2009-10-31 Matteo Palassini , A. P. Young

We study domain wall energies of two dimensional spin glasses. The scaling of these energies depends on the model's distribution of quenched random couplings, falling into three different classes. The first class is associated with the…

Disordered Systems and Neural Networks · Physics 2009-11-10 Carlo Amoruso , Enzo Marinari , Olivier C Martin , Andrea Pagnani

By quenched-randomly mixing local units of different spatial dimensionalities, we have studied Ising spin-glass systems on hierarchical lattices continuously in dimensionalities 1 =< d =< 3. The global phase diagram in temperature,…

Statistical Mechanics · Physics 2018-10-24 Bora Atalay , A. Nihat Berker

We propose a general method for studying systems that display excitations with arbitrarily low energy in their low-temperature phase. We argue that in a rectangular right prism geometry, with longitudinal size much larger than the…

We study domain-wall excitations in two-dimensional random-bond Ising spin systems on a square lattice with side length L, subject to two different continuous disorder distributions. In both cases an adjustable parameter allows to tune the…

Disordered Systems and Neural Networks · Physics 2009-05-06 O. Melchert , A. K. Hartmann

In this paper we try to estimate the lower critical dimension for replica symmetry breaking in spin glasses through the calculation of the additional free-energy required to create a domain wall between two different phases. This mechanism…

Condensed Matter · Physics 2009-10-22 S. Franz , G. Parisi , M. A. Virasoro

An efficient Monte Carlo method is extended to evaluate directly domain-wall free-energy for randomly frustrated spin systems. Using the method, critical phenomena of spin-glass phase transition is investigated in 4d +/-J Ising model under…

Disordered Systems and Neural Networks · Physics 2009-10-31 Koji Hukushima

Monte Carlo data of the two-dimensional Ising spin glass with bimodal interactions are presented with the aim of understanding the low-temperature physics of the model. An analysis of the specific heat, spin-glass susceptibility,…

Disordered Systems and Neural Networks · Physics 2007-05-23 Helmut G. Katzgraber , Lik Wee Lee , I. A. Campbell

Ground states of four-dimensional (d=4) EA Ising spin glasses are calculated for sizes up to 7x7x7x7 using a combination of a genetic algorithm and cluster-exact approximation. The ground-state energy of the infinite system is extrapolated…

Disordered Systems and Neural Networks · Physics 2009-10-31 Alexander K. Hartmann
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