Related papers: The effects of spin-spin interactions on magnetore…
We explore the magnetoresistance (MC) effect in an organic semiconductor device based on the magnetic field related bipolaron formation. By establishing a group of dynamic equations, we present the transition among spin-parallel,…
A model for magnetoresistance in positionally disordered organic materials is presented and solved using percolation theory. The model describes the effects of spin flips on hopping transport by considering the effect of spin dynamics on an…
It is shown that in organic semiconductors where organic magnetoresistance (OMAR) is observed, the exchange interaction between electrons and holes localized at different molecules leads to dynamic spin polarization in the direction of the…
We develop a theory of magnetoresistance based on variable-range hopping. An exponentially large, low-field and necessarily positive magnetoresistance effect is predicted in the presence of Hubbard interaction and spin-dynamics under…
Despite the fact that the problem of interference mechanism of magnetoresistance in semiconductors with hopping conductivity was widely discussed, most of existing studies were focused on the model of spinless electrons. This model can be…
A recently introduced percolative theory of unipolar organic magnetoresistance is generalized by treating the hyperfine interaction semiclassically for an arbitrary hopping rate. Compact analytic results for the magnetoresistance are…
We derive the kinetic equations for polaron hopping in organics that explicitly take into account the double occupation possibility and pair intersite correlations. The equations include simplified phenomenological spin dynamics and provide…
We describe a new regime for low-field magnetoresistance in organic semiconductors, in which the spin-relaxing effects of localized nuclear spins and electronic spins interfere. The regime is studied by the controlled addition of localized…
We derive kinetic equations describing injection and transport of spin polarized carriers in organic semiconductors with hopping conductivity via an impurity level. The model predicts a strongly voltage dependent magnetoresistance, defined…
We revisit the theory of magnetoresistance for a system of nanoscopic magnetic granules in metallic matrix. Using a simple model for the spin dependent perturbation potential of the granules, we solve Boltzmann equation for the spin…
We present a theoretical study of diluted magnetic semiconductors that treats the local sp-d exchange interaction J between the itinerant carriers and the Mn d electrons within a realistic band structure and goes beyond previous mean-field…
Theory of weak localization in two-dimensional high-mobility semiconductor systems is developed with allowance for the spin-orbit interaction. The obtained expressions for anomalous magnetoresistance are valid in the whole range of…
The transport properties of interacting electrons for which the spin degree of freedom is taken into account are numerically studied for small two dimensional diffusive clusters. On-site electron-electron interactions tend to delocalize the…
We review recent theoretical developments about the role of spins, electron-electron interactions, and spin-orbit coupling in metal nanoparticles and semiconductor quantum dots. For a closed system, in the absence of spin-orbit coupling or…
An attractive feature of magnetic adatoms and molecules for nanoscale applications is their superparamagnetism, the preferred alignment of their spin along an easy axis preventing undesired spin reversal. The underlying magnetic anisotropy…
The spin-orbit interaction in semiconductors is shown to result in an anisotropic contribution into the exchange Hamiltonian of a pair of localized conduction-band electrons. The anisotropic exchange interaction exists in semiconductor…
We consider the effect of electron-electron interaction on the density of states of disordered paramagnetic conductor in the presence of spin accumulation and magnetic field. We show that interaction correction to electron density of states…
We reconsider the theory of magnetoresistance in hopping semiconductors. First, we have shown that the random potential of the background impurities affects significantly preexponential factor of the tunneling amplitude which becomes to be…
Ferromagnetic polarons are self trapped states of an electron in a locally spin polarised environment. They occur close to the magnetic $T_c$ in low carrier density local moment magnets when the electron-spin coupling is comparable to the…
An experiment that shows the modulation of the Aharonov-Bohm oscillations of magneto-resistance in a mesoscopic ring is described. Possible theoretical explanations of this modulation due to the interaction of the electron spin with the…