Related papers: Ferromagnetic Polarons in Manganites
Electric-field controlled exchange bias in a heterostructure composed of the ferromagnetic manganite La0.7Sr0.3MO3 and the ferroelectric antiferromagnetic BiFeO3 has recently been demonstrated experimentally. By means of a microscopic model…
We solve the problem of fermionic pairing mediated by a massless boson in the limit of large coupling constant. At weak coupling, the transition temperature is exponentially small and superconductivity is robust against phase fluctuation.…
We develop a variational mean-field theory of the ferromagnetic transition in compounds like Lanthanum-Manganite within the framework of the Double-Exchange Model supplemented by modest disorder. We obtain analytical expressions for the…
The effects of interactions in a 2D electron system in a strong magnetic field of two degenerate Landau levels with opposite spins and at filling factors 1/2 are studied. Using the Chern-Simons gauge transformation, the system is mapped to…
We investigate the properties of composite polaron containing the effects of electron-phonon coupling and interaction between impurity and electron-hole pair. A model of a two-dimensional electron gas occupying the surface of…
A theoretical model for the reentrant charge-order transition in the manganites is examined. This transition is studied with a purely electronic model for the Mn electrons: the extended Hubbard model. The electron-phonon coupling results in…
Motivated by the existence of metal-insulator transition in one-dimensional non-interacting fermions in quasiperiodic and pseudorandom potentials, we studied interacting spinless fermion models using exact many-body Lanczos diagonalization…
We calculate the interaction kernel K for two-dimensional diffusive electrons. The screening of the Coulomb interaction together with the Fermi statistics induces a spin selection rule for electron-electron scattering so that in leading…
We present a detailed magnetic study of the Pr1/3Ca2/3MnO3 manganite, where we observe the presence of small ferromagnetic (FM) domains (diameter ~ 10A) immersed within the charge-ordered antiferromagnetic (AFM) host. Due to the interaction…
To understand spin interactions in materials of the Cu$_2$Sb structure type, inelastic neutron scattering of Fe$_2$As single crystals was examined at different temperatures and incident neutron energies. The experimental phonon spectra…
The Zener polarons recently found in half-doped manganites are usually seen as mixed valence entities ruled by a double exchange Hamiltonian involving only correlated electrons of the metals. They can however be considered as ferrimagnetic…
Neutron spectroscopy measurements reveal short-range spin correlations near and above the ferromagnetic-paramagnetic phase transition in manganite materials of the form La$_{1-x}A_{x}$MnO$_{3}$, including samples with an insulating ground…
We obtain the phase diagram of the double-exchange model at low electronic densities in the presence of electron-electron interactions. The single particle problem and its extension to low electronic densities, when a Wigner crystal of…
We discuss the ground state of Benzene dianion (Bz$^{2-}$) on the basis of the numerical diagonalization method of an effective model of $\pi$ orbitals. It is found that the ground state can be the spin singlet state, and the exchange…
The interaction between the electronic and structural degrees of freedom is central to several intriguing phenomena observed in condensed-matter physics. In magnetic materials, magnetic interactions couple to lattice degrees of freedom,…
We argue that the extension of the BCS theory to the strong-coupling regime describes the high-temperature superconductivity of cuprates and the colossal magnetoresistance (CMR) of ferromagnetic oxides if the phonon dressing of carriers and…
A mechanism for charge-ordered ferromagnetic phase in manganites is proposed. The mechanism is based on the double exchange in the presence of diagonal disorder. It is modeled by a combination of the Ising double-exchange and the…
Quantum entropies and state distances are analyzed in polaronic systems with short range (Holstein model) and long range (Fr$\ddot{o}$hlich model) electron-phonon coupling. These quantities are extracted by a variational wave function which…
What happens to ferromagnetism at the surfaces and interfaces of manganites? With the competition between charge, spin, and orbital degrees of freedom, it is not surprising that the surface behavior may be profoundly different than that of…
Here we present a detailed study of the THz and FIR response of the mixed perovskite manganite system Eu$_{1-x}$Ho$_x$MnO$_3$ for holmium concentrations x = 0.1 and 0.3. We compare the magnetic excitations of the four different magnetically…