Related papers: Effect of Jahn-Teller coupling on Curie temperatur…
We study a two dimensional, two-band double-exchange model for $e_g$ electrons coupled to Jahn-Teller distortions in the presence of quenched disorder using a recently developed Monte-Carlo technique. In the absence of disorder the…
We show that the critical temperature of a ferromagnetic phase transition in a quasi-two-dimensional hole gas confined in a diluted magnetic semiconductor quantum well strongly depends on the hole chemical potential and hole density. The…
We perform magnetic susceptibility and magnetic torque measurements on the organic $\kappa$-(BEDT-TTF)$_2$Hg(SCN)$_2$Br, which is recently suggested to host an exotic quantum dipole-liquid in its low-temperature insulating phase. Below the…
We investigate the classical antiferromagnetic Heisenberg model on the triangular lattice with up to third-nearest neighbor exchange couplings using the Nematic Bond Theory. This approach allows us to compute the free energy and the neutron…
The correlated motion of electrons in multi-orbital metallic ferromagnets is investigated in terms of a realistic Hubbard model with {\cal N}-fold orbital degeneracy and arbitrary intra- and inter-orbital Coulomb interactions U and J using…
A mechanism of non-magnetic Kondo effect is proposed on the basis of a multiorbital Anderson model coupled with dynamical Jahn-Teller (JT) phonons. An electron system coupled dynamically with JT phonons has a vibronic ground state with…
The electronic properties, exchange interactions, finite-temperature magnetism, and transport properties of random quaternary Heusler Ni$_{2}$MnSn alloys doped with Cu- and Pd-atoms are studied theoretically by means of {\it ab initio}…
The optical conductivity of the double exchange and the orbital degenerate Kondo lattice Hamiltonian (orbital t-J model) are invetigated by means of finite temperature diagonalization for different doping concentrations. The temperature…
We have calculated Heisenberg exchange parameters for bcc-Fe, fcc-Co, and fcc-Ni using the scalar-relativistic spin-polarized Green function technique within the tight-binding linear muffin-tin orbital method and by employing the magnetic…
Transition metal oxides incorporating Jahn-Teller (JT) ions Mn3+ (3d4) in manganites and Cu2+ (3d9) in cuprates exhibit outstanding magnetic and electronic properties, including colossal magnetoresistance (CMR) and high-temperature…
The effects of sintering temperature (Ts) and chemical substitution on the structural and magnetic properties of manganite compounds La1-xSrxMn1-yFeyO3 (0.025 <= x <= 0.7; y= 0.01,0.15) are explored in a search to optimize their…
We study the exchange interactions in half-metallic Heusler alloys using first-principles calculations in conjunction with the frozen-magnon approximation. The Curie temperature is estimated within both mean-field (MF) and…
We show that the effect of disorder on a Mott-Hubbard insulator of interacting electrons produces a quantum phase transition from an antiferromagnetic to a paramagnetic phase governed by a percolation of the singly occupied weakly…
Electronic structures, exchange interaction mechanism between magnetic ions and Curie temperature of Vanadium - doped Nitrides (AlN, GaN, and InN) are studied within KKR-LSDA-CPA. It is found that the ferromagnetic super-exchange…
We study phenomenologically on the basis of two bilinearly coupled Heisen- berg models the phase diagram of some ferrimagnetic substances. Calculations are performed with the help of Landau energy obtained through applying the…
The ferromagnetic properties of the spin-1 BEG model on finite-size Cayley tree are investigated using the exact recursion method. The spontaneous magnetization of the system is studied in detail for different values of the reduced…
We studied the exchange coupling and decoupling occurring in a nanocomposite spin system based on a 3D Heisenberg model by means of Monte Carlo numerical computation simulation. Different from conventional micromagnetism approach which…
We present a unified theory of magnetism and superconductivity of $UGe_2$. To this end, we consider part of $5f$ uranium electrons as mostly itinerant and other ones as mostly localized. The main feature that distinguishes the localized…
Exchange coupling parameters $J_{ij}$ in the Heisenberg model are crucial for describing magnetic behavior at the atomic level. In magnetic materials, spin fluctuations can be accompanied by a self-consistent electronic response --…
In the framework of the diagrammatic method with self-consistent field, the maximum on the temperature dependence of the susceptibility of a weakly doped narrow-band Hubbard magnet below the Curie temperature $T_{\rm C}$ is predicted. By…