Related papers: Universal properties of three-dimensional random-e…
We investigate the effects of magnetic inhomogeneities and thermal fluctuations on the magnetic properties of a rare earth intermetallic compound, Nd$_2$Fe$_{14}$B. The constrained Monte Carlo method is applied to a Nd$_2$Fe$_{14}$B bulk…
The low energy properties of the spin-1/2 random Heisenberg chain with ferromagnetic and antiferromagnetic interactions are studied by means of the density matrix renormalization group (DMRG) and real space renormalization group (RSRG)…
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 study the thermodynamics of one-dimensional quantum spin-1/2 Heisenberg ferromagnetic system with random antiferromagnetic impurity bonds. In the dilute impurity limit, we generalize the modified spin-wave theory for random spin chains,…
The numerical value of a universal quantity associated with the quantum critical regime, namely $\chi_u c^2/T$, for a two-dimensional (2D) dimerized spin-1/2 antiferromagnet is calculated using the quantum Monte Carlo simulations (QMC).…
The classical and the quantum, spin $S=1/2, versions of the uniaxially anisotropic Heisenberg antiferromagnet on a square lattice in a field parallel to the easy axis are studied using Monte Carlo techniques. For the classical version,…
The spin-1/2 anisotropic Heisenberg model with antiferromagnetic exchange interactions in the presence of a external magnetic field and a Dzyaloshinskii-Moriya interaction is studied by employing the usual mean-field approximation. The…
We compute the magnetic susceptibilities of interacting electrons in the presence of disorder on a two-dimensional square lattice by means of quantum Monte Carlo simulations. Clear evidence is found that at sufficiently low temperatures…
A one-dimensional model of electrons locally coupled to spin-1/2 degrees of freedom is studied by numerical techniques. The model is one in the class of $dynamic$ $Hubbard$ $models$ that describe the relaxation of an atomic orbital upon…
Phase transitions in the three-dimensional diluted Ising antiferromagnet in an applied magnetic field are analyzed numerically. It is found that random magnetic field in a system with spin concentration below a certain threshold induces a…
We report results of a Monte Carlo study of doped, diluted magnetic semiconductors in the low carrier density (insulating) regime. We find that the system undergoes a transition from a paramagnet at high temperatures to a ferromagnet at low…
We present results from Monte Carlo calculations investigating the properties of the homogeneous, spin-balanced unitary Fermi gas in three dimensions. The temperature is varied across the superfluid transition allowing us to determine the…
We study spin glass behavior in a random Ising Coulomb antiferromagnet in two and three dimensions using Monte Carlo simulations. In two dimensions, we find a transition at zero temperature with critical exponents consistent with those of…
In this work, a study of the magnetic behavior of the spinel ZnFe2O4 is presented by using the Monte Carlo simulations (MCS). The iron atoms provide the magnetism in this material. In fact, the magnetic spin of moment of the Fe3+ ions is…
Thermodynamic properties of a tetramer ferro-ferro-antiferro-antiferromagnetic Ising-Heisenberg bond alternating chain are investigated by the use of an exact mapping transformation technique. Exact results for the magnetization,…
A system of three-species fermions in one spatial dimension (1D) with a contact three-body interaction is known to display a scale anomaly. This anomaly is identical to that of a two-dimensional (2D) system of two-species fermions. The…
We study an exotic Kondo effect in a system consisting of two one-dimensional XX Heisenberg ferromagnetic spin $1/2$ chains (denoted by $\alpha = u, d$ for up and down chains) coupled to a quantum dot consisting of two localized spin $1/2$…
We simulate the spin-1/2 Heisenberg model with a spatially staggered anisotropy using first principles Monte Carlo method. In particular, the critical exponents $\beta/\nu$ and $\omega$ associated with the quantum phase transition induced…
The thermodynamics of finite open antiferromagnetic XXZ chains is studied using field theory, Bethe Ansatz and quantum Monte Carlo methods. For the susceptibility a parameter-free result as a function of the number of sites L and…
Motivated by the discovery of multiferroicity in the geometrically frustrated triangular antiferromagnet CuCrO$_2$ below its N\'eel temperature $T_N$, we investigate its magnetic and ferroelectric properties using ab initio calculations and…