Related papers: Monte Carlo Study of Doping Change and Disorder Ef…
Curie temperature and exponents are studied for the three-dimensional double-exchange model. Applying the O(N) Monte Carlo algorithm, we perform systematic finite-size scaling analyses on the data up to $20^3$ sites. The obtained values of…
Critical phenomena of ferromagnetic transition at finite temperatures are studied in double-exchange systems. In order to investigate strong interplay between charge and spin degrees of freedom, Monte Carlo technique is applied to include…
Doping change and distortion effect on the double-exchange ferromagnetism are studied within a simplified double-exchange model. The presence of distortion is modelled by introducing the Falicov-Kimball interaction between itinerant…
We have used Monte Carlo simulation techniques to obtain the magnetic phase diagram of the double exchange Hamiltonian. We have found that the Berry's phase of the hopping amplitude has a negligible effect in the value of the magnetic…
Ferromagnetic transition in three-dimensional double-exchange models is studied by the Monte Carlo method. Critical temperature $T_{\rm c}$ is precisely determined by finite-size scaling analysis. Strong spin fluctuations in this itinerant…
This article gives a comprehensive review on the recent studies of the double exchange systems using non-perturbative approaches; the dynamical mean-field theory and the Monte Carlo method. Investigations beyond mean-field type treatments…
Effect of randomness in the double-exchange model is studied. Large fluctuations and spatial random distribution of impurities are taken into account in an essentially exact manner by using the Monte Carlo calculation. The randomness…
Ferromagnetic transition in double-exchange systems is studied by non-equilibrium relaxation technique combined with Monte Carlo calculations. Critical temperature and critical exponents are estimated from relaxation of the magnetic moment.…
We study the phase diagram of the double exchange model, with antiferromagnetic interactions, in a cubic lattice both at zero and at finite temperature. There is a rich variety of magnetic phases, combined with regions where phase…
A model recently introduced for diluted magnetic semiconductors by Berciu and Bhatt (PRL 87, 107203 (2001)) is studied with a Monte Carlo technique, and the results are compared to Hartree-Fock calculations. For doping rates close to the…
Monte Carlo simulations, in which the Schrodinger equation is solved at each Monte Carlo sweep, are employed to assess the influence of magnetization fluctuations,short-range antiferromagnetic interactions, disorder, magnetic polaron…
Ferromagnetic systems described by the double exchange model are investigated. At temperatures close to the Curie temperature, and for a wide range of doping levels, the system is unstable toward phase separation. The chemical potential…
The phase diagram of the multivalent manganites $\rm La_{1-x}Ca_xMnO_3$, in space of temperature and doping $x$, is a challenge for the theoretical physics. It is an important test for the model used to study these compounds and the method…
The phase fluctuations of the condensate in doped antiferromagnets, described by a t-t'-J model and a suitable 1/N expansion, provide a mechanism for a Kosterlitz-Thouless (KT) type of transition to a superconducting state below T_{c}. In…
This discussion serves as an introduction to the use of Monte Carlo simulations as a useful way to evaluate the observables of a ferromagnet. Key background is given about the relevance and effectiveness of this stochastic approach and in…
The magnetic properties of Mn-doped ZnO semi-conductor have been investigated using the Monte Carlo method within the Ising model. The temperature dependences of the spontaneous magnetization, specific heat and magnetic susceptibility have…
Diagrammatic Monte Carlo -- the technique for numerically exact summation of all Feynman diagrams to high orders -- offers a unique unbiased probe of continuous phase transitions. Being formulated directly in the thermodynamic limit, the…
The coexistence of ferromagnetism and metallic conduction in doped manganites has long been explained by a double-exchange model in which the ferromagnetic exchange arises from the carrier hopping. We evaluate the zero-temperature spin…
We invesitgate the electronic correlation effect on the ground-state properties of the double exchange model for manganites by using a semiclassical approach and the slave-boson technique. It is shown that magnetic feild has a similar…
We present a study of the magnetic properties of the electron doped manganites Ca1-xYxMnO3 (for 0<=x<=0.25) in the paramagnetic regime. For the less doped samples (x<=0.1) the magnetic susceptibility, c(T), follows a Curie-Weiss (CW) law…