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Related papers: Complex-Temperature Singularities of Ising Models

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An approximate method is proposed for investigating complex-temperature properties of real-dimensional spin-glass models. The method uses the complex-temperature data of the ferromagnetic model on the same lattice. The universality line in…

Statistical Mechanics · Physics 2009-10-31 D. B. Saakian , E. E. Vogel

Many frustrated spin models on three-dimensional (3D) lattices are currently being investigated, both experimentally and theoretically, and develop new types of long-range orders in their respective phase diagrams. They present…

Strongly Correlated Electrons · Physics 2023-07-06 M. G. Gonzalez , B. Bernu , L. Pierre , L. Messio

We investigate the spin-spin correlation functions of Ising magnets at complex values of the temperature, T. For one-dimensional chain and ladder systems, we show the existence of a kind of helimagnetic order in the vicinity of contours…

Strongly Correlated Electrons · Physics 2013-04-24 F. Beichert , C. A. Hooley , R. Moessner , V. Oganesyan

The critical temperature of layered Ising models on triangular and honeycomb lattices are calculated in simple, explicit form for arbitrary distribution of the couplings.

Condensed Matter · Physics 2009-10-28 Ferenc Igloi , Peter Lajko

Magnetic properties of the 1D mixed spin-1/2 and spin-S (S >1/2) transverse Ising model in the presence of an external longitudinal magnetic field are calculated exactly by the use of the generalised decoration-iteration mapping…

Statistical Mechanics · Physics 2007-05-23 Jozef Strecka , Hana Cencarikova , Michal Jascur

The magnetic and entanglement thermal (equilibrium) properties in spin-1/2 Ising-Heisenberg model on a triangulated Kagome lattice are analyzed by means of variational mean-field like treatment based on Gibbs-Bogoliubov inequality. Because…

Quantum Physics · Physics 2010-12-30 N. S. Ananikian , L. N. Ananikyan , L. A. Chakhmakhchyan , A. N. Kocharian

We study the zeros in the complex plane of the partition function for the Ising model coupled to 2d quantum gravity for complex magnetic field and real temperature, and for complex temperature and real magnetic field, respectively. We…

High Energy Physics - Lattice · Physics 2009-10-30 J. Ambjorn , K. N. Anagnostopoulos , U. Magnea

For temperatures below the critical temperature, the magnetic susceptibility for the two-dimensional isotropic Ising model can be expressed in terms of an infinite series of multiple integrals. With respect to a parameter related to…

Mathematical Physics · Physics 2014-08-07 Craig A. Tracy , Harold Widom

A mixed spin-1/2 and spin-3/2 Ising model on a decorated square lattice with a nearest- neighbor interaction, next-nearest-neighbor bilinear interaction, three-site four-spin in- teraction and single-ion anisotropy is exactly investigated…

Statistical Mechanics · Physics 2017-08-23 Viliam Štubňa , Michal Jaščur

We present a high-temperature series expansion code for spin-1/2 Heisenberg models on arbitrary lattices. As an example we demonstrate how to use the application for an anisotropic triangular lattice with two independent couplings J1 and J2…

Strongly Correlated Electrons · Physics 2017-01-04 Andreas Hehn , Natalija van Well , Matthias Troyer

Ising model is famous in condensed matter and statistical physics. In this work we present a free-fermion formulation of the two-dimensional classical Ising models on the honeycomb, triangular and Kagom\'e lattices. Each Ising model is…

Statistical Mechanics · Physics 2025-10-16 De-Zhang Li , Xin Wang , Xiao-Bao Yang

The partition functions for two-dimensional nearest neighbour Ising model in a non-zero magnetic field have been derived for finite square lattices with the help of graph theoretical procedures, show-bit algorithm, enumeration of…

Statistical Mechanics · Physics 2010-06-03 G. Nandhini , M. Vinoth Kumar , M. V. Sangaranarayanan

We study the zero-temperature criticality of the Ising model on two-dimensional dynamical triangulations to contemplate its physics. As it turns out, an inhomogeneous nature of the system yields an interesting phase diagram and the physics…

High Energy Physics - Theory · Physics 2025-07-22 Jan Ambjørn , Yuki Sato , Tomo Tanaka

We report some new results on the complex-temperature (CT) singularities of $q$-state Potts models on the square lattice. We concentrate on the problematic region $Re(a) < 0$ (where $a=e^K$) in which CT zeros of the partition function are…

Condensed Matter · Physics 2014-10-13 Victor Matveev , Robert Shrock

We present an on-line library of unprecedented extension for high-temperature expansions of basic observables in the Ising models of general spin S, with nearest-neighbor interactions. We have tabulated through order beta^{25} the series…

High Energy Physics - Lattice · Physics 2014-11-17 P. Butera , M. Comi

There is no an accepted exact partition function (PF) for the two-dimensional (2D) Ising model with a non-zero external magnetic field to our knowledge. Here we infer an empirical PF for such an Ising model. We compare the PFs for two…

Statistical Mechanics · Physics 2019-08-27 Rong Qiang Wei

The phase diagram and the thermodynamics of the random field Ising model (RFIM) defined on a family of diamond hierarchical lattices of arbitrary dimension and scaling factor $b=2$ is investigated. The phase diagram is studied considering…

Disordered Systems and Neural Networks · Physics 2007-05-23 Alexandre Rosas , Sérgio Coutinho

The scaling of the transition temperature into an ordered phase close to a quantum critical point as well as the order parameter fluctuations inside the quantum critical region provide valuable information about universal properties of the…

Strongly Correlated Electrons · Physics 2016-04-29 Stephan Hesselmann , Stefan Wessel

Magnetic properties of a mixed spin-1/2 and spin-3/2 Ising model on honeycomb lattice are investigated within the framework of an exact star-triangle mapping transformation. The particular attention is focused on the effect of uniaxial and…

Statistical Mechanics · Physics 2007-05-23 Michal Jascur , Jozef Strecka

The critical behavior of the classical Ising model on a three-dimensional fractal lattice with Hausdorff dimension $d_H = \ln32 / \ln4 = 2.5$ is investigated using the higher-order tensor renormalization group (HOTRG) method. We determine…

Statistical Mechanics · Physics 2025-06-27 Jozef Genzor , Roman Krčmár , Hiroshi Ueda , Denis Kochan , Andrej Gendiar , Tomotoshi Nishino