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We report an effective functional form for the spin-spin correlation function of the 2D Ising model as a function of temperature and field. Although the Ising model has been well studied, no analytical result for the spin-spin correlation…

Statistical Mechanics · Physics 2013-07-29 Yan-Jiun Chen , Natalie M. Paquette , Benjamin B. Machta , James P. Sethna

A two-dimensional Ising model with nearest-neighbors ferromagnetic interactions is implemented in a Field Programmable Gate Array (FPGA) board.Extensive Monte Carlo simulations were carried out using an efficient hardware representation of…

Hardware Architecture · Computer Science 2016-02-10 Francisco Ortega-Zamorano , Marcelo A. Montemurro , Sergio A. Cannas , José M. Jerez , Leonardo Franco

The partition function of the 2D Ising model coupled to an external magnetic field is studied. We show that the sum over the spin variables can be reduced to an integration over a finite number of variables. This integration must be…

High Energy Physics - Theory · Physics 2007-05-23 Oscar Diego

We address the quantum-critical behavior of a two-dimensional itinerant ferromagnetic systems described by a spin-fermion model in which fermions interact with close to critical bosonic modes. We consider Heisenberg ferromagnets, Ising…

Strongly Correlated Electrons · Physics 2015-02-26 Matthias Einenkel , Hendrik Meier , Catherine Pépin , Konstantin B. Efetov

We develop a field theoretical approach to the classical two-dimensional models, particularly to 2D Ising model (2DIM) and $XYZ$ model, which is simple to apply for calculation of various correlation functions. We calculate the partition…

Strongly Correlated Electrons · Physics 2013-07-22 Sh. A. Khachatryan , A. G. Sedrakyan

We study the theoretical model of a ferromagnetic semiconductor as a system of randomly distributed Ising spins with a long-range exchange interaction. Using the density-of-states approach, we analytically obtain the magnetic susceptibility…

Strongly Correlated Electrons · Physics 2024-01-31 N. A. Bogoslovskiy , P. V. Petrov , N. S. Averkiev

The scaling of fluctuations in the distribution of ground-state energies or costs with the system size N for Ising spin glasses is considered using an extensive set of simulations with the Extremal Optimization heuristic across a range of…

Disordered Systems and Neural Networks · Physics 2022-05-20 Stefan Boettcher

The Ising model on ``thin'' graphs (standard Feynman diagrams) displays several interesting properties. For ferromagnetic couplings there is a mean field phase transition at the corresponding Bethe lattice transition point. For…

High Energy Physics - Lattice · Physics 2016-08-31 C. F. Baillie , D. A. Johnston , J-P. Kownacki

In this paper we propose and realize (the code is publicly available at https://github.com/Thrawn1985/2D-Partition-Function) an algorithm for exact calculation of partition function for planar graph models with binary spins. The complexity…

Disordered Systems and Neural Networks · Physics 2016-11-04 Yakov M. Karandashev , Magomed Yu. Malsagov

We study the belief propagation algorithm for the graph bi-partitioning problem, i.e. the ground state of the ferromagnetic Ising model at a fixed magnetization. Application of a message passing scheme to a model with a fixed global…

Disordered Systems and Neural Networks · Physics 2010-06-16 P. Sulc , L. Zdeborova

The random field Ising model driven by a slowly varying uniform external field at zero temperature provides a caricature of several threshold activated systems. In this model, the non-equilibrium response of the system can be obtained…

Statistical Mechanics · Physics 2009-11-10 Prabodh Shukla

The 3D one-component spin system in an external magnetic field is studied using the collective variables method. The integration of the partition function of the system over the phase space layers is performed in the approximation of the…

Statistical Mechanics · Physics 2007-05-23 I. V. Pylyuk , M. P. Kozlovskii

Ising machines (IMs) are specialized devices designed to efficiently solve combinatorial optimization problems (COPs). They consist of artificial spins that evolve towards a low-energy configuration representing a problem's solution. Most…

We demonstrate that a quantum field theory (QFT) in general two-dimensional curved spacetimes can be realized by a system of quantum spins or qubits. We consider a spin-1/2 model on a one-dimensional ring with spatially and temporally…

High Energy Physics - Theory · Physics 2025-05-28 Shunichiro Kinoshita , Keiju Murata , Daisuke Yamamoto , Ryosuke Yoshii

We present a general procedure for calculating the exact partition function of an Ising model on a periodic chain in presence of magnetic field considering both open and closed boundary conditions. Using same procedure on a quasiperiodic…

Statistical Mechanics · Physics 2007-05-23 Susanta Bhattacharya , Samir K. Paul

Hamiltonians for general multi-state spin-glass systems with Ising symmetry are derived for both sequential and synchronous updating of the spins. The possibly different behaviour caused by the way of updating is studied in detail for the…

Disordered Systems and Neural Networks · Physics 2016-08-16 D. Bollé , J. Busquets Blanco

We study the complexity of computing average quantities related to spin systems, such as the mean magnetization and susceptibility in the ferromagnetic Ising model, and the average dimer count (or average size of a matching) in the…

Computational Complexity · Computer Science 2013-03-07 Alistair Sinclair , Piyush Srivastava

Given a graphical model (GM), computing its partition function is the most essential inference task, but it is computationally intractable in general. To address the issue, iterative approximation algorithms exploring certain local…

Machine Learning · Computer Science 2019-05-15 Sejun Park , Eunho Yang , Se-Young Yun , Jinwoo Shin

We study the identity testing problem in the context of spin systems or undirected graphical models, where it takes the following form: given the parameter specification of the model $M$ and a sampling oracle for the distribution…

Data Structures and Algorithms · Computer Science 2019-06-21 Ivona Bezakova , Antonio Blanca , Zongchen Chen , Daniel Štefankovič , Eric Vigoda

A powerful existing technique for evaluating statistical mechanical quantities in two-dimensional Ising models is based on constructing a matrix representing the nearest neighbor spin couplings and then evaluating the Pfaffian of the…

Disordered Systems and Neural Networks · Physics 2013-04-16 Creighton K. Thomas , A. Alan Middleton