Related papers: Electronic phase separation in the pyrochlore doub…
Competition between the ferromagnetic double-exchange interaction and the super-exchange antiferromagnetic interaction is theoretically studied in the presence of geometrical frustration. As increasing the super-exchange interaction, the…
The generic changes of the electronic compressibility in systems which show magnetic instabilities is studied. It is shown that, when going into the ordered phase, the compressibility is reduced by an amount comparable to the its original…
We consider the nanoscale electronic phase separation in a wide class of different materials, mostly in strongly correlated electron systems. The phase separation turns out to be quite ubiquitous manifesting itself in different situations,…
Recent computational studies of models for manganese oxides have revealed a rich phase diagram, not anticipated in early calculations in this context performed in the 1950's and 60's. In particular, the transition between the…
We study the competition between different possible ground states of the double-exchange model with strong ferromagnetic exchange interaction between itinerant electrons and local spins. Both for classical and quantum treatment of the local…
An analytical and numerical study of the one-dimensional double and super-exchange model is presented. A phase separation between ferromagnetic and anti-ferromagnetic phases occurs at low super-exchange interaction energy. When the…
We study the possibility of nanoscale phase separation in manganites in the framework of the double exchange model. The homogeneous canted state of this model is proved to be unstable toward the formation of small ferromagnetic droplets…
By using a realist microscopic model, we study the electric and magnetic properties of the interface between a half metallic manganite and an insulator. We find that the lack of carriers at the interface debilitates the double exchange…
We present extensive large-scale dynamical simulations of phase-separated states in the double exchange model. These inhomogeneous electronic states that play a crucial role in the colossal magnetoresistance phenomenon are composed of…
We consider the double exchange model at very low densities. The conditions for the formation of self-trapped magnetic polarons are analyzed using an independent polaron model. The issue of phase separation in the low density region of the…
From thermodynamic analysis we demonstrate that during metal-insulator transitions in pure matters, a nonequilibrium homogeneous state may be unstable against charge density modulations with certain wavelengths, and thus evolves to the…
We consider a model with competing double-exchange (ferromagnetic) and super-exchange (anti-ferromagnetic) interactions in the regime where phase separation takes place. The presence of a long range Coulomb interaction frustrates a…
The double-exchange model, which has been extensively studied in the context of colossal magneto-resistance in perovskite manganese oxides, is known to exhibit a ferromagnetic metallic state at low temperatures because of the interplay…
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…
Phase separation and a tendency to form inhomogeneous structures seems to be a generic property of systems with strongly correlated electrons. After shortly summarising the existing theoretical results in this direction, I concentrate on…
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…
Our single crystal study of the magneto-thermal and transport properties of the pyrochlore iridate Eu2Ir2O7 reveals a continuous phase transition from a paramagnetic metal to an antiferromagnetic insulator for a sample with stoichiometry…
We study phase separation frustrated by the long-range Coulomb interaction in two dimensional electronic systems with emphasys in the case of a metallic and an insulating phase. We find that two-dimensional systems are more prone to…
We study Ising pyrochlores by means of Monte Carlo simulations. We cover a set of exchange constants ranging from the frustrated ferromagnetic case (spin-ice) to the fully-ordered "all-in--all-out" antiferromagnet in the dipolar model,…
Within massive gravity, we construct a gravity dual for insulator/metal phase transition and colossal magnetoresistance (CMR) effect found in some manganese oxides materials. In heavy graviton limit, a remarkable magnetic-field-sensitive DC…