the effects of conduction band nonparabolicity, aluminum concentration and external electric field on the charge density and binding energy of an on-center hydrogenic donor impurity in a spherical quantum dot which is located at the center of a cylindrical nano-wire are studied. the energy eigenvalues and the corresponding wave functions are calculated using finite difference approximation with...

We have measured the picosecond time-resolved cyclotron resonance of photogenerated transient carriers in undoped InSb/Al0.09In0.91Sb quantum wells by two-color pump-probe spectroscopy in a magnetic field. The strong conduction-band nonparabolicity of InSb causes the average cyclotron mass of the electrons, which we monitor directly in time, to decrease as the electrons relax towards the band e...

We present an efficient two-band k·p theory which accurately describes the six lowest conduction band valleys in silicon. By comparing the model with full band pseudo-potential calculations we demonstrate that the model captures both the nonparabolicty effects and the stress-induced band structure modification for general stress conditions. It reproduces the stress dependence of the effective m...

We start from the fourth-order nonparabolic and anisotropic conduction band bulk dispersion relation to obtain a one-band effective Hamiltonian, which we apply to an AlGaSb symmetric double-barrier structure with resonant energies significantly (more than 200 meV) above the well bottom. The spin-splitting is described by the k(3) Dresselhaus spin-orbit coupling term modifying only the effective...

The composition dependence of the in-plane conduction band effective mass in strained 15nm-thick lattice-mismatched GatJn,As/InP single quantum wells was determined by conventional cyclotron and optically detected cyclotron resonance techniques. Our results are in agreement with a self-consistent calculation taking into account effects due to nonparabolicity, confinement, strain, and finite two...

We present a fast and robust method for the full-band solution of the Schrödinger equation on a grid, with the goal of achieving a more complete description of high energy states and realistic temperatures. Using fast Fourier transforms, the Schrödinger equation in the one band approximation can be expressed as an iterative eigenvalue problem for arbitrary shapes of the conduction band. The res...

Electron, hole, and exciton states of multishell CdS/HgS/CdS quantumdot quantum well nanocrystals are determined by use of a multiband theory that includes valence-band mixing, modeled with a 6-band Luttinger-Kohn Hamiltonian, and nonparabolicity of the conduction band. The multiband theory correctly describes the recently observed dark-exciton ground state and the lowest, optically active, bri...

We have investigated the optical properties of unstrained GaAs/AlxGa1−xAs quantum dot/well systems with the aim of studying the influence of confinement on the effective exciton mass, as determined from the photoluminescence line shift in high magnetic fields 50 T . The effective exciton mass is found to be more than twice the value for bulk GaAs. We attribute this to an enhanced nonparabolicit...

We predict a hysteretic three-photon cyclotron resonance in narrow-gap semiconductors driven by two laser beams with their frequency difference near the cyclotron frequency. This effect is based on the Doppler and Lorentz nonlinear mechanisms and the nonparabolicity of the conduction band. A CO(2) laser intensity of 10(5)-10(6) W/cm(2) at 10.6 and 9.4 microm is required for observation of the e...