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Related papers: Critical exponents of the random-field O(N) model

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The ferromagnet-to-paramagnet transition of the four-dimensional random-field Ising model with Gaussian distribution of the random fields is studied. Exact ground states of systems with sizes up to 32^4 are obtained using graph theoretical…

Disordered Systems and Neural Networks · Physics 2009-11-07 Alexander K. Hartmann

A lot of progress has been made recently in our understanding of the random-field Ising model thanks to large-scale numerical simulations. In particular, it has been shown that, contrary to previous statements: the critical exponents for…

Disordered Systems and Neural Networks · Physics 2018-07-10 Nikolaos G. Fytas , Victor Martin-Mayor , Marco Picco , Nicolas Sourlas

We show that the critical scaling behavior of random-field systems with short-range interactions and disorder correlations cannot be described in general by only two independent exponents, contrary to previous claims. This conclusion is…

Disordered Systems and Neural Networks · Physics 2015-06-15 Gilles Tarjus , Ivan Balog , Matthieu Tissier

We review the theoretical description of the random field Ising and $O(N)$ models obtained from the functional renormalization group, either in its nonperturbative implementation or, in some limits, in perturbative implementations. The…

Disordered Systems and Neural Networks · Physics 2020-04-22 Gilles Tarjus , Matthieu Tissier

We study the quantum phase transition in the two-dimensional random Ising model in a transverse field by Monte Carlo simulations. We find results similar to those known analytically in one-dimension: the dynamical exponent is infinite and,…

Disordered Systems and Neural Networks · Physics 2016-08-31 C. Pich , A. P. Young

In extensive Monte Carlo simulations the phase transition of the random field Ising model in three dimensions is investigated. The values of the critical exponents are determined via finite size scaling. For a Gaussian distribution of the…

Condensed Matter · Physics 2009-10-28 Heiko Rieger

The two-dimensional (2D) random-bond Ising model has a novel multicritical point on the ferromagnetic to paramagnetic phase boundary. This random phase transition is one of the simplest examples of a 2D critical point occurring at both…

Statistical Mechanics · Physics 2009-10-28 Sora Cho , Matthew P. A. Fisher

We investigate the critical behavior of three-dimensional random-field Ising systems with both Gauss and bimodal distribution of random fields and additional the three-dimensional diluted Ising antiferromagnet in an external field. These…

Statistical Mechanics · Physics 2009-10-31 A. K. Hartmann , U. Nowak

We compute critical exponents of O(N) models in fractal dimensions between two and four, and for continuos values of the number of field components N, in this way completing the RG classification of universality classes for these models. In…

High Energy Physics - Theory · Physics 2015-05-08 A. Codello , N. Defenu , G. D'Odorico

Recent work on exact renormalization group flow equations has pointed out the possibility to study critical phenomena in continuous dimension D of space. In an investigation of the O(N) model the dimension N of the fields may be seen as a…

High Energy Physics - Theory · Physics 2007-05-23 H. Ballhausen

The critical exponent beta =0.16 +- 0.02 for the random-field Ising model order parameter is determined using extinction-free magnetic x-ray scattering for Fe(0.85)Zn(0.15)F2 in magnetic fields of 10 and 11 T. The observed value is…

Disordered Systems and Neural Networks · Physics 2009-11-07 F. Ye , L. Zhou , S. Larochelle , L. Lu , D. P. Belanger , M. Greven , D. Lederman

The Nishimori point of the random bond Ising model is a prototype of renormalization group fixed points with strong disorder. We show that the exact correlation length and crossover critical exponents at this point can be identified in two…

Statistical Mechanics · Physics 2025-04-18 Gesualdo Delfino

The phase transition of the three--dimensional random field Ising model with a discrete ($\pm h$) field distribution is investigated by extensive Monte Carlo simulations. Values of the critical exponents for the correlation length, specific…

High Energy Physics - Lattice · Physics 2019-06-05 Heiko Rieger , A. P. Young

The phase transition of the three--dimensional random field Ising model with a discrete ($\pm h$) field distribution is investigated by extensive Monte Carlo simulations. Values of the critical exponents for the correlation length, specific…

Condensed Matter · Physics 2009-10-22 Heiko Rieger , A. P. Young

The random-field Ising model is one of the few disordered systems where the perturbative renormalization group can be carried out to all orders of perturbation theory. This analysis predicts dimensional reduction, i.e., that the critical…

Disordered Systems and Neural Networks · Physics 2017-04-12 Nikolaos G. Fytas , Victor Martin-Mayor , Marco Picco , Nicolas Sourlas

We consider the random transverse-field Ising model in $d=3$ dimensions with long-range ferromagnetic interactions which decay as a power $\alpha > d$ with the distance. Using a variant of the strong disorder renormalization group method we…

Statistical Mechanics · Physics 2016-06-08 István A. Kovács , Róbert Juhász , Ferenc Iglói

We show that current estimates of the critical exponents of the three-dimensional random-field Ising model are in agreement with the exponents of the pure Ising system in dimension 3 - theta where theta is the exponent that governs the…

Statistical Mechanics · Physics 2010-03-25 Th. Jolicoeur , J. C. Le Guillou

A review is given on some recent developments in the theory of the Ising model in a random field. This model is a good representation of a large number of impure materials. After a short repetition of earlier arguments, which prove the…

Statistical Mechanics · Physics 2008-02-03 T. Nattermann

We provide a resolution of one of the long-standing puzzles in the theory of disordered systems. By reformulating the functional renormalization group (FRG) for the critical behavior of the random field Ising model in a superfield…

Statistical Mechanics · Physics 2015-05-27 Matthieu Tissier , Gilles Tarjus

We have studied the one dimensional Dyson hierarchical model in presence of a random field. This is a long range model where the interactions scale with the distance with a power law-like form J(r) ~ r^{-\rho} and we can explore mean field…

Disordered Systems and Neural Networks · Physics 2014-07-23 Giorgio Parisi , Jacopo Rocchi
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