相关论文: Dimensional crossover and the magnetic transition …
We have developed a new magnetoelectric material based on Ga doped {\alpha}-Fe2O3 in rhombohedral phase. The material is a canted ferromagnet at room temperature and showing magneto-electric properties. The experimental results of electric…
The effect of Fe substitution on Mn sites in the colossal magnetoresistive compounds La0.65Ca0.35Mn1-xFexO3 with 0.01<x<0.1 have been studied. A careful study in the magnetic properties has been carried out by the measurement of ac…
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…
We reinvestigate the bandwidth-control and doping-control Mott transitions (BCMT and DCMT) from a spin liquid Mott insulator to a Fermi liquid metal based on the slave-rotor representation of the Hubbard model,\cite{Florens} where the Mott…
It has been recently shown that the double exchange Hamiltonian, with weak antiferromagnetic interactions, has a richer variety of first and second order transitions than previously anticipated, and that such transitions are consistent with…
We study the transition at T=0 from a ferromagnetic insulating to a ferromagnetic metallic phase in manganites as a function of hole doping using an effective low-energy model Hamiltonian proposed by us recently. The model incorporates the…
Inspired by the strong experimental evidence for the coexistence of localized and itinerant charge carriers close to the metal-insulator transition in the ferromagnetic phase of colossal magnetoresistive manganese perovskites, for a…
We study theoretically the phase diagram of perovskite manganites taking into account the double degeneracy of the $e_g$ orbitals in a $Mn^{3+}$ ion. A rich phase diagram is obtained in the mean field theory at zero temperature as functions…
The structural and magnetic properties of transition metal-doped Mn$_3$SnC are studied with an aim to understand the effect of transition metal atom on magnetostructural properties of the antiperovskite compound. The doped…
We investigate the interplay between spin and orbital correlations in monolayer and bilayer manganites using an effective spin-orbital t-J model which treats explicitly the e_g orbital degrees of freedom coupled to classical t_{2g} spins.…
We study how doping destroys the AF order in the layered cuprates within the framework of the charge--transfer insulator concept. We use the criterion of stability of the AF background to show that the stability problem is one of the main…
The crystallographic and magnetic phase diagram of the n=2 layered manganite La2-2xSr1+2xMn2O7 in the region x=>0.5 has been studied using temperature dependent neutron powder diffraction. The magnetic phase diagram reveals a progression of…
The ground-state magnetic properties of hexagonal equiatomic alloy of nominal composition Mn_{0.8}Fe_{0.2}NiGe were investigated through dc magnetization and heat capacity measurements. The alloy undergoes first order martensitic transition…
In view of recent experiments, indicating the spatial coexistence of conducting and insulating regions in the ferromagnetic metallic phase of doped manganites, we propose a refined mixed-phase description. The model is based on the…
We propose a novel mechanism for exchange-induced exciton-magnon absorptions via hopping between two antiferromagnetically coupled sites and a simultaneous magnetic dipole transition to an excited orbital state. The obtained selection rules…
We investigate the magnetic instabilities of the two-dimensional model of interacting e_g electrons for hole doping away from two electrons per site in the mean-field approximation. In particular, we address the occurrence of orbitally…
We derive a realistic microscopic model for doped colossal magnetoresistance manganites, which includes the dynamics of charge, spin, orbital and lattice degrees of freedom on a quantum mechanical level. The model respects the SU(2) spin…
Based on the $t$-$t'$-$t''$-$J$ model we have calculated the dynamical spin susceptibilities in the antiferromagnetic (AF) phase for electron-doped cuprates, by use of the slave-boson mean-field theory and random phase approximation.…
We present a comprehensive analysis of the magnetic excitations and electronic properties of fully quantum double-exchange ferromagnets, i.e., systems where ferromagnetic ordering emerges from the competition between spin, charge, and…
We propose a unified magnetic phase diagram of cuprate superconductors. A new feature of this phase diagram is a broad intermediate doping region of quantum-critical, $z=1$, behavior, characterized by temperature independent $T_1T/T_{\rm…