Related papers: Ferromagnetic Polarons in Manganites
We use neutron scattering to study the lattice and magnetic structure of the layered half-doped manganite Pr$_{0.5}$Ca$_{1.5}$MnO$_4$. On cooling from high temperature, the system first becomes charge- and orbital- ordered (CO/OO) near…
Understanding mechanisms of quantum ordering in strongly correlated systems remains a central challenge in condensed matter physics, with implications for designing novel quantum materials. Here, we investigate kinetic antiferromagnetism on…
Strongly correlated electrons on an Apollonian network are studied using the Hubbard model. Ground-state and thermodynamic properties, including specific heat, magnetic susceptibility, spin-spin correlation function, double occupancy and…
The phase diagram of the ferromagnetic Kondo model for manganites is investigated using computational techniques. In clusters of dimensions 1 and 2, Monte Carlo simulations in the limit where the localized spins are classical show a rich…
We consider a nanoscale system consisting of Manganite-ferromagnet and Cuprate-superconductor multilayers in a spin valve configuration. The magnetization of the bottom Manganite-ferromagnet is pinned by a Manganite-antiferromagnet. The…
We study the boundary between ferromagnetic and non-ferromagnetic ground state of a double-exchange system with quenched disorder for arbitrary relation between Hund exchange coupling and electron band width. The boundary is found both from…
We apply the Dynamical Mean Field Theory to the problem of charge ordering. In the normal state as well as in the Charge Ordered (CO) state the existence of polarons, i.e. electrons strongly coupled to local lattice deformation, is…
In insulating lanthanides, unquenched orbital momentum and weak crystal-field (CF) splitting of the atomic $J$ multiplet at lanthanide ions result in a highly ranked (multipolar) exchange interaction between them and a complex…
Controlling spin wave excitations in magnetic materials underpins the burgeoning field of magnonics. Yet, little is known about how magnons interact with the conduction electrons of itinerant magnets, or how this interplay can be…
We studied ferromagnetism in the one-dimensional Hubbard model with doubly degenerate atomic orbitals by means of the density-matrix renormalization-group method and obtained the ground-state phase diagrams. It was found that ferromagnetism…
We study paramagnetic - ferromagnetic transition due to exchange interaction between classical localized magnetic moments and conduction electrons. We formulate the Dynamical Mean Field Approximation equations for arbitrary electron…
The phase diagram of the simplest approximation to Double-Exchange systems, the bosonic Double-Exchange model with antiferromagnetic super-exchange coupling, is fully worked out by means of Monte Carlo simulations, large-N expansions and…
The electronic properties of many transition metal oxide systems require new ideas concerning the behaviour of electrons in solids for their explanation. A recent example, subsequent to that of cuprate superconductors, is of rare earth…
We study the ground-state properties of the SU(N)-generalization of the Kondo-lattice model in one dimension when the Kondo coupling J_K (both ferromagnetic and antiferromagnetic) is sufficiently strong. Both cases can be realized using…
The two-orbital model for manganites with both non-cooperative and cooperative Jahn-Teller phonons is studied at hole density x=0.5 using Monte Carlo techniques. The phase diagram is obtained varying the electron-phonon coupling and the…
The transport properties of the ferromagnetic Kondo lattice model in one dimension are studied via bosonization methods. The antiferromagnetic fluctuations, which normally appear because of the RKKY interactions, are explicitly taken into…
We discuss magnetotransport in a low density electron gas coupled to spin fluctuations near and above a ferromagnetic transition. Provided the density is low enough ($n \lesssim 1/\xi^{3}(T)$, with $\xi(T)$ the ferromagnetic correlation…
We study the {\it ferromagnetic} (FM) Kondo lattice model in the strong coupling limit (double exchange (DE) model). The DE mechanism proposed by Zener to explain ferromagnetism has unexpected properties when there is more than one…
We study strongly correlated electrons on a kagome lattice at 1/6 and 1/3 filling. They are described by an extended Hubbard Hamiltonian. We are concerned with the limit |t|<<V<<U with hopping amplitude t, nearest-neighbor repulsion V and…
The spin correlations of the bilayer manganite $La_{1.2}Sr_{1.8}Mn_{2}O_{7}$ have been studied using neutron scattering. On cooling within the paramagnetic state, we observe purely two-dimensional behavior with a crossover to…