Magnetotransport properties of a pseudomorphic GaAs/ Ga0.8In0.2As/Ga0.75Al0.25As heterostructure are investigated in pulsed magnetic fields up to 50 T and at temperatures of T =1.4 K and 4.2 K. The structure studied consists of a Si δ-layer parallel to a Ga0.8In0.2As quantum well (QW). The dark electron density of the structure is ne = 1.67×1016 m−2. By illumination the density can be increased...

Metalorganic chemical vapor deposition-grown In0.4Ga0.6As0.995N0.005 quantum well ~QW! lasers have been realized, at an emission wavelength of 1.295 mm, with threshold and transparency current densities as low as 211 A/cm ~for L52000 mm! and 75 A/cm, respectively. The utilization of a tensile-strained GaAs0.67P0.33 buffer layer and GaAs0.85P0.15 barrier layers allows a highly-compressively-stra...

Quantum well (QW) resonances in Fe(001)/MgO/Fe/MgO/Fe double barrier magnetic tunnel junctions are calculated from first principles. By including the Coulomb blockade energy due to the finite size islands of the middle Fe film, we confirm that the oscillatory differential resistance observed in a recent experiment [T. Nozaki, Phys. Rev. Lett. 96, 027208 (2006)10.1103/PhysRevLett.96.027208] orig...

We have developed a simple model for the carrier capture and escape processes in quantum-well ~QW! lasers, which yields an analytical expression for the ratio of the carrier capture and escape times. It predicts a decrease in the escape time with injected carrier density due to the state filling effect. It also shows an exponential dependence of the escape time on the effective barrier height a...

Despite the rapid development of the quantum well ~QW! infrared technology, the intrinsic properties of the QW infrared photodetectors ~QWIPs! have not been directly measured under the operating conditions of the detector. In this work, we introduce a characterization technique, which utilizes the surface corrugation to probe the absorption coefficient and the photoconductive gain of a QWIP und...

The relative strengths of Rashba and Dresselhaus terms describing the spin-orbit coupling in semiconductor quantum well (QW) structures are extracted from photocurrent measurements on n-type InAs QWs containing a two-dimensional electron gas (2DEG). This novel technique makes use of the angular distribution of the spin-galvanic effect at certain directions of spin orientation in the plane of a ...

We treat a quantum walk (QW) on the line whose quantum coin at each vertex tends to be the identity as the distance goes to infinity. We obtain a limit theorem that this QW exhibits localization with not an exponential but a “power-law” decay around the origin and a “strongly” ballistic spreading called bottom localization in this paper. This limit theorem implies the weak convergence with line...

We present a theoretical approach that allows for calculation of optical functions ${\mathrm{Cu}}_{2}\mathrm{O}$ quantum well (QW) with Rydberg excitons, in an external magnetic field arbitrary strength. Both Faraday and Voigt configurations are considered the energetic region $p$ excitons. use real density matrix effective electron-hole potential, which enable us to derive analytical expressio...

Efforts to implement semiconductor-based spintronic devices have been crippled by the lack of an efficient and practical means to electrically inject spin-polarized carriers into a semiconductor heterostructure. Spin injection from semimagnetic semiconductor contacts (ZnMnSe/AlGaAs/GaAs) has produced electron spin polarizations of ~ 85% in the GaAs QW [1]. Several factors potentially limit spin...