In electron-doped GaAs, we use scanning Kerr-rotation microscopy to locally probe and spatially resolve the depolarization of electron spin distributions by transverse magnetic fields. The shape of these local Hanleeffect curves provides a measure of the spin lifetime as well as spin transport parameters including drift velocity, mobility and diffusion length. Asymmetries in the local Hanle dat...

With the recent discovery of very long hole spin decoherence times in GaAs/AlGaAs heterostructures of more than 70 ns in two-dimensional hole systems, using the hole spin as a viable alternative to electron spins in spintronic applications seems possible. Furthermore, as the hyperfine interaction with the nuclear spins is likely to be the limiting factor for electron spin lifetimes in zero dime...

The technologically important prediction of Auger recombination lifetimes in semiconductors is addressed by means of a fully first-principles formalism, based on precise energy bands and wave functions provided by the full-potential linearized augmented plane wave code. The minority carrier Auger lifetime is determined by two related approaches: (i) a direct evaluation within Fermi's golden rul...

The optical-absorption coefficient o.(m) in heavily doped nand p-type GaAs is evaluated for comparison with the observed values of Casey et al. The purpose is to test the theory of electrons in heavily disordered systems derived by Sa-yakanit and the absorption matrix element (ME) which follows from this theory. The present calculation of a(m) begins with the density of electron states (DOS) an...

Here we demonstrate, via a modified transferprinting technique, that electrochemically fabricated porous silicon (PSi) distributed Bragg reflectors (DBRs) can serve as the basis of high-quality hybrid microcavities compatible with most forms of photoemitters. Vertical microcavities consisting of an emitter layer sandwiched between 11and 15-period PSi DBRs were constructed. The emitter layer inc...

The effect of spin-orbit interaction was studied in a high-quality $p$-AlGaAs/GaAs/AlGaAs structure with square quantum well using acoustic methods. grown on GaAs (100) substrate symmetrically doped carbon both sides the well. Shubnikov--de Haas--type oscillations ac conductance two-dimensional holes were measured. At low magnetic field $B<2$ T, undergo beating induced by interaction. Analys...

The electrical isolation of Zn-doped GaAs layers grown by metalorganic chemical vapor deposition was studied using H, Li, C, and O ion implantation. The ion mass did not play a significant role in the stability of isolation, and a similar activation energy of ;(0.6360.03 eV) was obtained for isolation using either H or O ions. Furthermore, the isolation was stable against isochronal annealing u...

Si-doped GaAs/AlGaAs multi-quantum wells structures grown by molecular beam epitaxy on (100) and (311)B GaAs substrates have been studied by using conventional deep-level transient spectroscopy (DLTS) and high-resolution Laplace DLTS techniques. One dominant electron-emitting level is observed in the quantum wells structure grown on (100) plane whose activation energy varies from 0.47 to 1.3 eV...

Large positive (P) magnetoresistance (MR) has been observed in parallel magnetic fields in a single 2D layer in a delta-doped GaAs/AlGaAs heterostructure with a variable-range-hopping (VRH) mechanism of conductivity. Effect of large PMR is accompanied in strong magnetic fields by a substantial change in the character of the temperature dependence of the conductivity. This implies that spins pla...

The interactions between carriers and fields in semiconductors at low frequencies (<100 GHz) can be adequately described by numerical solution of the Boltzmann transport equation coupled with Poisson’s equation. As the frequency approaches the THz regime, the quasi-static approximation fails and full-wave dynamics must be considered. Here, we review recent advances in global modeling techniques...