Magnetization steps and relevant cluster statistics for a diluted Heisenberg layer: Nearest-neighbor cluster model on the square lattice

2005 ◽  
Vol 72 (6) ◽  
Author(s):  
Valdir Bindilatti ◽  
Yaacov Shapira
Keyword(s):  
Cluster Model ◽  
Nearest Neighbor ◽  
Square Lattice ◽  
Neighbor Cluster

THE CRITICAL BEHAVIOR OF THE 2D SPIN-1 ISING MODEL WITH THE BILINEAR AND POSITIVE BIQUADRATIC NEAREST NEIGHBOR INTERACTIONS ON A CELLULAR AUTOMATON

2004 ◽  
Vol 15 (10) ◽  
pp. 1425-1438 ◽  
Author(s):  
A. SOLAK ◽  
B. KUTLU
Keyword(s):  
Cellular Automaton ◽  
Phase Boundary ◽  
Critical Behavior ◽  
Nearest Neighbor ◽  
Finite Size ◽  
Square Lattice ◽  
Two Dimensional ◽  
Finite Size Scaling ◽  
Creutz Cellular Automaton ◽  
Beg Model

The two-dimensional BEG model with nearest neighbor bilinear and positive biquadratic interaction is simulated on a cellular automaton, which is based on the Creutz cellular automaton for square lattice. Phase diagrams characterizing phase transitions of the model are presented for comparison with those obtained from other calculations. We confirm the existence of the tricritical points over the phase boundary for D/K>0. The values of static critical exponents (α, β, γ and ν) are estimated within the framework of the finite size scaling theory along D/K=-1 and 1 lines. The results are compatible with the universal Ising critical behavior except the points over phase boundary.

SUPERCONDUCTING CLASSES IN THE EXTENDED HUBBARD MODEL

1996 ◽  
Vol 10 (12) ◽  
pp. 1397-1423 ◽  
Author(s):  
MASA-AKI OZAKI ◽  
EIJI MIYAI ◽  
TOMOAKI KONISHI ◽  
KAORU HANAFUSA
Keyword(s):  
Hubbard Model ◽  
Nearest Neighbor ◽  
Mean Field ◽  
Square Lattice ◽  
Extended Hubbard Model ◽  
S Wave ◽  
Ferromagnetic Order ◽  
Numerical Studies ◽  
The Mean

This paper describes group theoretical classification of superconducting states (SC) in the extended Hubbard model with on-site repulsion (U), nearest neighbor attraction (V) and nearest neighbour exchange interaction (J) on the two-dimensional square lattice using the mean field approach. By decomposing the pairing interaction into irreducible parts; A1g, B1g and Eu of D4h point symmetry, we have derived two singlet SCs (s-wave and d-wave) from A1g and B1g, eight triplet SCs from Eu. The first three types of triplet SC have pairing by electrons with antiparallel spin, the second two types have pairing by electrons with equal spin and the last three types are non-unitary and have pairing by only up-spin electrons. We showed that three non-unitary states have to be accompanied with a ferromagnetic order from the structure of the maximal little groups. We performed numerical studies for these SCs. For parameters and electron density favorable for the ferromagnetic order, a non-unitary SC coexistent with ferromagnetism is most stable.

A LATTICE STATISTICS MODEL DERIVED FROM THE TWO-LAYER ADSORPTION PROBLEM

1965 ◽  
Vol 43 (6) ◽  
pp. 980-985
Author(s):  
D. D. Betts ◽  
D. L. Hunter
Keyword(s):  
Nearest Neighbor ◽  
Chemical Potential ◽  
Physical Adsorption ◽  
Square Lattice ◽  
Lateral Interaction ◽  
Lattice Statistics ◽  
Regular Lattice ◽  
Adsorption Sites ◽  
Layer Adsorption ◽  
Gas Molecules

A model is proposed for the physical adsorption of two layers of gas molecules at the sites of a regular lattice with lateral interaction between nearest-neighbor molecules. The model is more complicated than the two-dimensional Ising model. However, for a particular relation among the three energy parameters and at a particular value of the chemical potential the model simplifies considerably. For the simplified model and a square lattice of adsorption sites, high- and low-temperature series expansions for the specific heat have been obtained and the transition temperature estimated.

scholarly journals Complete catalog of ground-state diagrams for the general three-state lattice-gas model with nearest-neighbor interactions on a square lattice

2019 ◽  
Vol 21 (11) ◽  
pp. 6216-6223 ◽  
Author(s):  
Daniel Silva ◽  
Per Arne Rikvold
Keyword(s):  
Phase Diagrams ◽  
Ground State ◽  
Lattice Gas ◽  
Nearest Neighbor ◽  
Square Lattice ◽  
Temperature Phase ◽  
Zero Temperature ◽  
Dimensional Parameter ◽  
State Diagrams ◽  
Solid Foundation

The fifteen topologically different zero-temperature phase diagrams in the model's full, five-dimensional parameter space provide a solid foundation for studies at finite temperatures.

scholarly journals Quantum phase transitions of a square-lattice Heisenberg antiferromagnet with two kinds of nearest-neighbor bonds: A high-order coupled-cluster treatment

2000 ◽  
Vol 61 (21) ◽  
pp. 14607-14615 ◽  
Author(s):  
Sven E. Krüger ◽  
Johannes Richter ◽  
Jörg Schulenburg ◽  
Damian J. J. Farnell ◽  
Raymond F. Bishop
Keyword(s):  
Phase Transitions ◽  
Nearest Neighbor ◽  
Quantum Phase Transitions ◽  
High Order ◽  
Quantum Phase ◽  
Square Lattice ◽  
Coupled Cluster ◽  
Heisenberg Antiferromagnet

GROUND STATE OF THE 2D EXTENDED HUBBARD MODEL WITH MORE THAN NEAREST-NEIGHBOR INTERACTIONS

2012 ◽  
Vol 26 (29) ◽  
pp. 1250156 ◽  
Author(s):  
S. HARIR ◽  
M. BENNAI ◽  
Y. BOUGHALEB
Keyword(s):  
Phase Diagram ◽  
Hubbard Model ◽  
Ground State ◽  
State Energy ◽  
Nearest Neighbor ◽  
Finite Size ◽  
Square Lattice ◽  
Extended Hubbard Model ◽  
Eigenvalues And Eigenvectors ◽  
Repulsion Energy

We investigate the ground state phase diagram of the two dimensional Extended Hubbard Model (EHM) with more than Nearest-Neighbor (NN) interactions for finite size system at low concentration. This EHM is solved analytically for finite square lattice at one-eighth filling. All eigenvalues and eigenvectors are given as a function of the on-site repulsion energy U and the off-site interaction energy Vij. The behavior of the ground state energy exhibits the emergence of phase diagram. The obtained results clearly underline that interactions exceeding NN distances in range can significantly influence the emergence of the ground state conductor–insulator transition.

A simple statistics-based nearest neighbor cluster detection algorithm

2015 ◽  
Vol 48 (3) ◽  
pp. 918-932 ◽  
Author(s):  
Gerhard X. Ritter ◽  
José-A. Nieves-Vázquez ◽  
Gonzalo Urcid
Keyword(s):  
Nearest Neighbor ◽  
Detection Algorithm ◽  
Cluster Detection ◽  
Neighbor Cluster

INTERFACE INSTABILITY IN DRIVEN LATTICE GASES

Fractals ◽  
1993 ◽  
Vol 01 (04) ◽  
pp. 954-958 ◽  
Author(s):  
G. SZABÓ ◽  
A. SZOLNOKI ◽  
T. ANTAL ◽  
I. BORSOS
Keyword(s):  
Lattice Gas ◽  
Nearest Neighbor ◽  
Interfacial Instability ◽  
Lattice Gases ◽  
Square Lattice ◽  
Wave Number ◽  
Material Transport ◽  
Interface Instability ◽  
Amplification Rate ◽  
Lattice Gas Models

In driven lattice-gas models, the enhanced material transport along the interfaces results in an instability of the planar interfaces and leads to the formation of multistrip states. To study the interfacial instability, Monte Carlo simulations are performed on different square lattice-gas models. The amplification rate of a periodic perturbation depends on the wave number k; it has a positive maximum at a characteristic value of k on the analogy of the Mullins-Sekerka instability. Significant differences have been found in the dependence of amplification rate on k when comparing the systems with nearest neighbor repulsive and nearest and next-nearest neighbor attractive interactions. The results agree qualitatively with theories neglecting the fluctuations.

scholarly journals A two-nearest-neighbor structure model and analysis of low-expansion Fe–Ni alloys

2021 ◽  
pp. 2141009
Author(s):  
Hai-Lian Hong ◽  
Hao Gao ◽  
Chi-Hsin Yang ◽  
Kun-Chieh Wang ◽  
Hui-Xian Yan
Keyword(s):  
Atomic Structure ◽  
Short Range ◽  
Nearest Neighbor ◽  
Periodic Oscillation ◽  
Structure Model ◽  
Ordered Structure ◽  
Practical Procedure ◽  
Ni Alloys ◽  
Neighbor Cluster ◽  
Selection Of

The main goal of the study is to introduce a two-nearest-neighbor structure model for analyzing low-expansion Fe–Ni alloys. A two-shell atomic structure model is proposed to accurately locate the compositions of the alloy. In the presented model, the Cowley parameters of the alloy short-range ordered structure are considered. The selection of the first-nearest-neighbor cluster is determined, and the number and composition ratio of the second-nearest-neighbor atoms are evaluated by means of the spherical periodic oscillation model. The results show that the developed formula can provide a practical procedure for the composition design of low-expansion Fe–Ni alloys.

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