Related papers: Anisotropic XY antiferromagnets in a field
The magnetic properties of anisotropic films have been studied using 3D-neutron polarization analysis. The experimental facts refer to essential distinction of the sample states, magnetized in opposite directions. For an explanation of…
We present the results of Monte Carlo simulations for the antiferromagnetic classical XXZ model with easy-plane exchange anisotropy on the triangular lattice, which causes frustration of the spin alignment. The behaviour of this system is…
We determine the quantum phase diagram of the antiferromagnetic spin-1/2 XXZ model on the triangular lattice as a function of magnetic field and anisotropic coupling $J_z$. Using the density matrix renormalization group (DMRG) algorithm in…
The quantum phase transition between paramagnetic and antiferromagnetic phases of the Kondo lattice model with Ising anisotropy in the intersite exchange is studied within the framework of extended dynamical mean-field theory.…
Identifying the nature of a spin-flop (SFO) transition, first- or second-order (FO or SO), remains a major challenge in condensed-matter physics due to the technically undistinguishable effect of misalignment between applied-field direction…
We present the first correlated-electron theory of metamagnetism in strongly anisotropic antiferromagnets. Quantum-Monte-Carlo techniques are used to calculate the field vs. temperature phase diagram of the infinite-dimensional Hubbard…
We simulate antiferromagnetic thin films. Dipole-dipole and antiferromagnetic exchange interactions as well as uniaxial and quadrupolar anisotropies are taken into account. Various phases unfold as the corresponding parameters, J, D and C,…
Motivated by experiments on (Sr,Ca,La)_14 Cu_24 O_41, a two-dimensional Ising model with mobile defects and a two-dimensional anisotropic Heisenberg antiferromagnet have been proposed and studied recently. We extend previous investigations…
Critical behavior of three-dimensional classical frustrated antiferromagnets with a collinear spin ordering and with an additional twofold degeneracy of the ground state is studied. We consider two lattice models, whose continuous limit…
Quantum phase transitions between the magnetically ordered and disordered states are studied for the two-dimensional antiferromagnetic quantum spin systems with ladder, plaquette, and mixed-spin structures. Starting with properly chosen…
A relation between geometric phases and criticality of spin chains is established. As a result, we show how geometric phases can be exploited as a tool to detect regions of criticality without having to undergo a quantum phase transition.…
Motivated by recent experiments on the metamagnet FeBr2, anomalies of the magnetization and the specific heat in the antiferromagnetic phase of related spin models are studied systematically using Monte Carlo simulations. In particular, the…
Motivated by the recent experimental observations [Phys Rev B 57 R11051 (1998)] of transverse spin ordering in FeBr_2 induced by a magnetic field with oblique angle to the easy axis of the system, we performed extensive Monte Carlo…
Synthetic antiferromagnets with strong perpendicular anisotropy can be modeled by layered Ising antiferromagnets. Accounting for the fact that in the experimental systems the ferromagnetic layers, coupled antiferromagnetically via spacers,…
The antiferromagnetic Heisenberg model on a stacked triangular geometry with a finite number of layers is studied using Monte Carlo methods. A topological phase transition occurs at finite temperature for all film thicknesses. Our results…
Finite size scaling for a first order phase transition where a continuous symmetry is broken is developed using an approximation of Gaussian probability distributions with a phenomenological "degeneracy" factor included. Predictions are…
Quantum-classical escape-rate transition has been studied for two general forms of magnetic anisotropy in ferrimagnetic or antiferromagnetic particles. It is found that the range of the first-order transition is greatly reduced as the…
Extensive histogram Monte-Carlo simulations of the XY antiferromagnet on a stacked triangular lattice reveal exponent estimates which strongly favor a scenario of mean-field tricritical behavior for the spin-order transition. The…
We study the antiferromagnetic O(N) model in the F_4 lattice. Monte Carlo simulations are applied for investigating the behavior of the transition for N=2,3. The numerical results show a first order nature but with a large correlation…
The frustrated spin-1/2 model with weakly anisotropic ferromagnetic nearest-neighbor and antiferromagnetic next-nearest-neighbor exchanges is studied with use of variational mean-field approach, scaling estimates of the infrared…