We study the electronic and magneto-transport properties of multiferroic oxide-based structures and explore their
potential for spintronic applications. In particular, we point out the possibility of using the two dimensional
electron gas (2DEG) formed at the interface of helimagnetic oxides as a spin-field-effect transistor and a flash
memory device. The operation of this device relies on the fact that the topology of the multiferroic oxide local
magnetic moments results in a resonant momentum-dependent effective spin-orbit interaction acting on 2DEG.
The spin polarization dephasing is strongly suppressed which is crucial for functionality. The effective spin-orbit
interaction and the carrier spin precession phase depend linearly on the magnetic spiral helicity which, due to the
magnetoelectric coupling, is electrically controllable. We also consider helical multiferroic tunnel junctions with
a normal metallic layer as the bottom electrode and a ferromagnetic layer as the other electrode. It is shown
that the tunnel-magneto-resistance is spatially dependent and is controllable via an external electric field.
We show theoretically how charge distribution in low-dimensional semiconductor heterostructures is manipulated and controlled by means of linearly polarized, strongly asymmetric electromagnetic pulses. In particular we point out the possibility of generating a charge polarization and charge currents in mesoscopic rings and how these non-equilibrium phenomena can be utilized as a source for electromagnetic radiation and for the generation of magnetic states in the rings. Possible relaxation and decoherence pathways are investigated by means of the density matrix formalism and typical time scales for the survival of the generated non-equilibrium charge distributions are estimated.
We study the charge dynamics in a double quantum well and in ballistic mesoscopic rings driven by half-cycle pulses. It is shown that such pulses can be utilized to localize, within femtoseconds, and control, for picoseconds, the electronic motion in a Ga<sub>1-<i>x</i></sub>Al<sub><i>x</i></sub>As based double quantum well. To identify the pulse parameters that appropriate for an efficient control process we developed a simplified analytical model and corroborated the results by performing full numerical calculations. We also show that when a thin ballistic mesoscopic ring is subjected to a linearly polarized HCP a post-pulse (and therefore field-free) polarization is induced in the ring. The non-equilibrium post-pulse polarization oscillates in the ring as long as the coherence is preserved and decays on a time scale determined by the relaxation time.