Spin oscillations in transient diffusion of a spin pulse in n-type semiconductor quantum wells

By studying the time and spatial evolution of a pulse of the spin polarization in $n$-type semiconductor quantum wells, we highlight the importance of the off-diagonal spin coherence in spin diffusion and transport. Spin oscillations and spin polarization reverse along the the direction of spin diffusion in the absence of the applied magnetic field are predicted from our investigation.Comment: 5 pages, 4 figures, accepted for publication in PR

General boundary conditions for the envelope function in multiband k.p model

We have derived general boundary conditions (BC) for the multiband envelope functions (which do not contain spurious solutions) in semiconductor heterostructures with abrupt heterointerfaces. These BC require the conservation of the probability flux density normal to the interface and guarantee that the multiband Hamiltonian be self--adjoint. The BC are energy independent and are characteristic properties of the interface. Calculations have been performed of the effect of the general BC on the electron energy levels in a potential well with infinite potential barriers using a coupled two band model. The connection with other approaches to determining BC for the envelope function and to the spurious solution problem in the multiband k.p model are discussed.Comment: 15 pages, 2 figures; to be published in Phys. Rev. B 65, March 15 issue 200

Radiation-induced oscillatory magnetoresistance as a sensitive probe of the zero-field spin splitting in high mobility GaAs/AlGaAs devices

We suggest an approach for characterizing the zero-field spin splitting of high mobility two-dimensional electron systems, when beats are not readily observable in the Shubnikov-de Haas effect. The zero-field spin splitting and the effective magnetic field seen in the reference frame of the electron is evaluated from a quantitative study of beats observed in radiation-induced magnetoresistance oscillations.Comment: 4 pages, 4 color figure

The spin-orbit interaction as a source of new spectral and transport properties in quasi-one-dimensional systems

We present an exact theoretical study of the effect of the spin-orbit (SO) interaction on the band structure and low temperature transport in long quasi-one-dimensional electron systems patterned in two-dimensional electron gases in zero and weak magnetic fields. We reveal the manifestations of the SO interaction which cannot in principle be observed in higher dimensional systems.Comment: 5 pages including 5 figures; RevTeX; to appear in Phys.Rev.B (Rapid Communications

Effect of the spin-orbit interaction on the band structure and conductance of quasi-one-dimensional systems

We discuss the effect of the spin-orbit interaction on the band structure, wave functions and low temperature conductance of long quasi-one-dimensional electron systems patterned in two-dimensional electron gases (2DEG). Our model for these systems consists of a linear (Rashba) potential confinement in the direction perpendicular to the 2DEG and a parabolic confinement transverse to the 2DEG. We find that these two terms can significantly affect the band structure introducing a wave vector dependence to subband energies, producing additional subband minima and inducing anticrossings between subbands. We discuss the origin of these effects in the symmetries of the subband wave functions.Comment: 15 pages including 14 figures; RevTeX; to appear in Phys.Rev.B (15 Nov 1999