We restudy the phase diagram of the 2D-Ising model with competing interactions J<Subscript>1</Subscript> on nearest neighbour and J<Subscript>2</Subscript> on next-nearest neighbour bonds via Monte-Carlo simulations. We present the finite temperature phase diagram and introduce computational methods which allow us to calculate transition...</subscript></subscript>

We implement a Chern-Simons (CS) contribution into the compact QED<Subscript>3</Subscript> description of the antiferromagnetic Heisenberg model in two dimensions at zero temperature. The CS term allows for the conservation of the SU(2) symmetry of the quantum spin system and fixes the flux through a plaquette to be a...</subscript>

The partition function (Fisher) zeros of the Q-state Potts model with three-site interactions on a zigzag ladder are studied by a transfer-matrix approach. This Q-state model is proposed as a description of helix-coil transition in homopolymers. The Fisher zeros are exactly derived for arbitrary...

Through Monte Carlo Simulation, the well-known majority-vote model has been studied with noise on directed random graphs. In order to characterize completely the observed order–disorder phase transition, the critical noise parameter qc, as well as the critical exponents β/ν, γ/ν and 1/ν...

The energy gap of the 1D AF-Heisenberg model in the presence of both uniform (H) and staggered (h) magnetic fields is investigated using the exact diagonalization technique. The opening of the gap in the presence of a staggered field is found to scale with h<Superscript>ν</Superscript>, where ν=ν(H) is the critical...</superscript>

We study the one-dimensional isotropic spin-1 Heisenberg magnet with antiferromagnetic nearest-neighbor (nn) and next-nearest-neighbor (nnn) interactions by using the modified spin wave theory (MSWT). The ground state energy and the singlet-triplet energy gap are obtained for several values of...

We develop a model for ferromagnetic resonance in systems with competing uniaxial and cubic anisotropies. This model applies to (i) magnetic materials with both uniaxial and cubic anisotropies, and (ii) magnetic nanoparticles with effective core and surface anisotropies; We numerically compute...

We have studied the behavior of the energy gap of the 1D AF spin-<InlineEquation ID="Equ1"> <EquationSource Format="TEX">$\frac{1}{2}$</EquationSource> </InlineEquation> XXZ model in a transverse magnetic field (h) using the exact diagonalization technique. The ground state phase diagram consists of two spin-flop and paramagnetic phases. Using a modified finite-size scaling...</equationsource></inlineequation>

We compute the magnetic susceptibility and specific heat of the spin-<InlineEquation ID="Equ2"> <EquationSource Format="TEX">$\frac{1}{2}$</EquationSource> </InlineEquation> Heisenberg model on the kagome lattice with high-temperature expansions and exact diagonalizations. We compare the results with the experimental data on ZnCu<Subscript>3</Subscript>(OH)<Subscript>6</Subscript>Cl<Subscript>2</Su bscript> obtained by Helton et al. [Phys. Rev. Lett....<//su></subscript></subscript></subscript></equationsource></inlineequation>