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Related papers: Fermionic TAP-equations

200 papers

The stability of spin-glass (SG) phase is analyzed in detail for a fermionic Ising SG (FISG) model in the presence of a magnetic transverse field $\Gamma$. The fermionic path integral formalism, replica method and static approach have been…

Disordered Systems and Neural Networks · Physics 2009-11-13 S. G. Magalhaes , F. M. Zimmer , C. V. Morais

The spherical mean field approximation of a spin-1 model with p-body quenched disordered interaction is investigated. Depending on temperature and chemical potential the system is found in a paramagnetic or in a glassy phase and the…

Disordered Systems and Neural Networks · Physics 2012-03-06 Ulisse Ferrari , Luca Leuzzi

We consider the thermodynamics of an infinite-range Ising p-spin glass model with an additional r-spin ferromagnetic interaction. For r=2 there is a continuous transition to a ferromagnetic phase, while for r>2 the transition is first…

Disordered Systems and Neural Networks · Physics 2009-11-07 Peter Gillin , Hidetoshi Nishimori , David Sherrington

The free energy of TAP-solutions for the SK-model of mean field spin glasses can be expressed as a nonlinear functional of local terms: we exploit this feature in order to contrive abstract REM-like models which we then solve by a classical…

Disordered Systems and Neural Networks · Physics 2023-07-19 Nicola Kistler , Marius Alexander Schmidt , Giulia Sebastiani

We have analyzed a fermionic infinite-ranged quantum Heisenberg spin glass with BCS coupling in real space in the presence of a magnetic field. It has been possible to locate the transition line between the normal paramagnetic phase (NP)…

Statistical Mechanics · Physics 2007-05-23 S. G. Magalhaes , A. A. Schmidt

We provide evidence for spin glass related magnetic gaps in the fermionic density of states below the freezing temperature. Model calculations are presented and proposed to be relevant for explaining resistivity measurements which observe a…

Disordered Systems and Neural Networks · Physics 2009-10-30 R. Oppermann , B. Rosenow

We study the high-temperature regime of a mean-field spin glass model whose couplings matrix is orthogonally invariant in law. The magnetization of this model is conjectured to satisfy a system of TAP equations, originally derived by Parisi…

Probability · Mathematics 2022-12-22 Zhou Fan , Yufan Li , Subhabrata Sen

We study the thermodynamic properties and the phase diagrams of a multi-spin antiferromagnetic spherical spin-glass model using the replica method. It is a two-sublattice version of the ferromagnetic spherical p-spin glass model. We…

Disordered Systems and Neural Networks · Physics 2012-05-22 D. B. Liarte , C. S. O. Yokoi

We have examined the role of the BCS pairing mechanism in the formation of the magnetic moment and henceforth a spin glass (SG) phase by studying a fermionic Sherrington-Kirkpatrick model with a local BCS coupling between the fermions. This…

Statistical Mechanics · Physics 2016-08-31 S. G. Magalhaes , Alba Theumann

The study of the mean-field static solution of the Random Blume-Emery-Griffiths-Capel model, an Ising-spin lattice gas with quenched random magnetic interaction, is performed. The model exhibits a paramagnetic phase, described by a stable…

Statistical Mechanics · Physics 2009-11-10 Andrea Crisanti , Luca Leuzzi

The free energy landscape of the Sherrington-Kirkpatrik (SK) Ising spin glass is simple in the framework of the Thouless-Anderson-Palmer (TAP) equations as each solution (which are minima of the free energy) has associated with it a nearby…

Disordered Systems and Neural Networks · Physics 2022-03-29 T. Aspelmeier , M. A. Moore

In the context of the p-spin spherical model, we introduce a method for the computation of the number of stationary points of any nature (minima, saddles, etc.) of the TAP free energy. In doing this we clarify the ambiguities related to the…

Disordered Systems and Neural Networks · Physics 2009-10-30 Andrea Cavagna , Irene Giardina , Giorgio Parisi

We solve the Thouless-Anderson-Palmer (TAP) variational principle associated to the spherical pure $p$-spin mean field spin glass Hamiltonian and present a detailed phase diagram. In the high temperature phase the maximum of variational…

Disordered Systems and Neural Networks · Physics 2022-07-07 David Belius , Marius A. Schmidt

We consider the spherical spin glass model defined by a combination of the pure 2-spin spherical Sherrington-Kirkpatrick Hamiltonian and the ferromagnetic Curie-Weiss Hamiltonian. In the large system limit, there is a two-dimensional phase…

Probability · Mathematics 2018-10-17 Jinho Baik , Ji Oon Lee , Hao Wu

By using frustration-preserving hard-spin mean-field theory, we investigated the phase transition dynamics in the three-dimensional field-free $\pm J$ Ising spin glass model. As the temperature $T$ is decreased from paramagnetic phase at…

Statistical Mechanics · Physics 2021-09-29 Ozan S. Sarıyer

A zero temperature dynamics of Ising spin glasses and ferromagnets on random graphs of finite connectivity is considered, like granular media these systems have an extensive entropy of metastable states. We consider the problem of what…

Statistical Mechanics · Physics 2009-11-07 David S. Dean , Alexandre Lefèvre

The number $\langle N_s\rangle$ of solutions of the equations of Thouless, Anderson and Palmer for p--spin interaction spin glass models is calculated. Below a critical temperature $T_c$ this number becomes exponentially large, as it is in…

Condensed Matter · Physics 2009-10-22 H. Rieger

We consider a tapping dynamics, analogous to that in experiments on granular media, on spin glasses and ferromagnets on random thin graphs. Between taps, zero temperature single spin flip dynamics takes the system to a metastable state.…

Statistical Mechanics · Physics 2009-11-07 David S. Dean , Alexandre Lefevre

We consider the infinite-range deterministic spin models with Hamiltonian $H=\sum_{i,j=1}^N J_{i,j}\sigma_i\sigma_j$, where $J$ is the quantization of a chaotic map of the torus. The mean field (TAP) equations are derived by summing the…

Condensed Matter · Physics 2009-10-28 I. Borsari , M. Degli esposti , S. Graffi , F. Unguendoli

We report progress in understanding the fermionic Ising spin glass with arbitrary filling. A crossover from a magnetically disordered single band phase via two intermediate bands just below the freezing temperature to a 3-band structure at…

Strongly Correlated Electrons · Physics 2007-05-23 R. Oppermann , H. Feldmann