Quantum dots based on spin properties of semiconductor heterostructures

The possibility of a novel type of semiconductor quantum dots obtained by spatially modulating the spin-orbit coupling intensity in III-V heterostructures is discussed. Using the effective mass model we predict confined one-electron states having peculiar spin properties. Furthermore, from mean field calculations (local-spin-density and Hartree-Fock) we find that even two electrons could form a bound state in these dots.Comment: 9 pages, 3 figures. Accepted in PRB (Brief Report) (2004

Electronic structure of nuclear-spin-polarization-induced quantum dots

We study a system in which electrons in a two-dimensional electron gas are confined by a nonhomogeneous nuclear spin polarization. The system consists of a heterostructure that has non-zero nuclei spins. We show that in this system electrons can be confined into a dot region through a local nuclear spin polarization. The nuclear-spin-polarization-induced quantum dot has interesting properties indicating that electron energy levels are time-dependent because of the nuclear spin relaxation and diffusion processes. Electron confining potential is a solution of diffusion equation with relaxation. Experimental investigations of the time-dependence of electron energy levels will result in more information about nuclear spin interactions in solids

Observation of two relaxation mechanisms in transport between spin split edge states at high imbalance

Using a quasi-Corbino geometry to directly study electron transport between spin-split edge states, we find a pronounced hysteresis in the I-V curves, originating from slow relaxation processes. We attribute this long-time relaxation to the formation of a dynamic nuclear polarization near the sample edge. The determined characteristic relaxation times are 25 s and 200 s which points to the presence of two different relaxation mechanisms. The two time constants are ascribed to the formation of a local nuclear polarization due to flip-flop processes and the diffusion of nuclear spins.Comment: Submitted to PR

Dynamics of transformation of conduction electrons into charge-density-wave soliton at low temperatures

The analytical model which describes the dynamics of transformation of conduction electrons into nonlinear charge-carrying excitations of CDW in quasi-one-dimensional Peierls-Frohlich conductors is formulated and studied by the inverse scattering transformation method. The pair of self-trapped conduction electrons transform into a charged 2л-кіпк localized in a single conducting chain and surrounded by dipoles in neighboring chain

Quasi-one-dimensional charge density wave in electromagnetic field arbitrarily oriented to conducting chains : Generalized Frohlich relations

We derive equations for the collective CDW-curent transverse conducting chains in a quasi-one-dimensional CDW-conductor. Generalized Fröhlich relations between the transverse currents and phase gradients are due to the polarization corrections to the (1+1) chiral anomaly Lagrangean. The CDW Hall constant RCDW is calculated, RCDW ~ T2c/ICDW, where Tc is the critical temperature of the Peierls transition, and ICDW is the nonlinear CDW current in the direction parallel to the conducting chain