相关论文: Double Exchange Model for Magnetic Hexaborides

To understand anomalous transport properties of EuB$_6$, we have studied the spin-polaron Hamiltonian incorporating the electron-phonon interaction. Assuming a strong exchange interaction between the carriers and the localized spins, the…

The microscopic basis for the stability of itinerant ferromagnetism in correlated electron systems is examined. To this end several routes to ferromagnetism are explored, using both rigorous methods valid in arbitrary spatial dimensions, as…

Based on the standard many-fermion field theory, the authors construct models describing ultracold fermions in a 1D optical lattices by implementing a mode expansion of the fermionic field operator where modes, in addition to space…

We consider a theory of a two-component Dirac fermion localized on a (2+1) dimensional brane coupled to a (3+1) dimensional bulk. Using the fermionic particle-vortex duality, we show that the theory has a strong-weak duality that maps the…

Effect of randomness in the double-exchange model is studied. Large fluctuations and spatial random distribution of impurities are taken into account in an essentially exact manner by using the Monte Carlo calculation. The randomness…

In doped manganites, the strong electron-phonon coupling due to the Jahn-Teller effect localizes the conduction-band electrons as polarons. This results in polarons are carriers responsible for transport and ferromagnetic ordering rather…

Electron transport in a finite one dimensional quantum spin chain (with ferromagnetic exchange) is studied within an $s-d$ exchange Hamiltonian. Spin transfer coefficients strongly depend on the sign of the $s-d$ exchange constant. For a…

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…

Charge transport is a revealing probe of the quantum properties of materials. Strong interactions can blur charge carriers resulting in a poorly understood "quantum soup". Here we study the conductivity of the Fermi-Hubbard model, a testing…

Fermi liquid theory has been a foundation in understanding the electronic properties of materials. For weakly interacting two-dimensional (2D) electron or hole systems, electron-electron interactions are known to introduce quantum…

The influence of long-range spin and charge fluctuations on spectra of the two-dimensional fermionic Hubbard model is considered using the strong coupling diagram technique. Infinite sequences of diagrams containing ladder inserts, which…

Using Path Integral Monte Carlo we have calculated exchange frequencies as electrons undergo ring exchanges in a ``clean'' 2d Wigner crystal as a function of density. The results show agreement with WKB calculations at very low density, but…

In our short review, we consider the transport properties of strongly correlated Fermi systems like heavy fermion metals and high-$T_c$ superconductors. Their transport properties are defined by strong inter-particle interaction forming…

We explored the magnetic behavior of a common two-phase nanomagnetic system by Monte Carlo computer simulation of a modified Heisenberg model on a 3D complex lattice with single- and cluster-spins. The effect of exchange coupling between…

We report on a simple calculation of the magnetotransport in cuprate superconductors, based on the nearly antiferromagnetic Fermi liquid (spin fluctuation) model. We find that the model explains all important features seen experimentally:…

The paper is devoted to the applications of the theory of dynamical systems to the theory of transport phenomena in metals in the presence of strong magnetic fields. More precisely, we consider the connection between the geometry of the…

We show that antiferromagnetic spin-density wave order in the two-dimensional Hubbard model yields a drop of the charge carrier density as observed in recent transport measurements for cuprate superconductors in high magnetic fields upon…

The temperature dependence of the transport properties of the metallic phase of a frustrated Hubbard model on the hypercubic lattice at half-filling are calculated. Dynamical mean-field theory, which maps the Hubbard model onto a single…

Thermoelectric power measurements on the heavy fermion antiferromagnet Ce(Ru0.92Rh0.08)2Si2 under magnetic field (H) show clearly that the antiferromagnetic state below the critical field Hc ~ 2.8T can be fully decoupled from the…

We present a model study of ferromagnetic films consisting of free Bloch electrons coupled to localized moments (Kondo lattice films). By mapping the local interaction onto an effective Heisenberg Hamiltonian we obtain temperature and…