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We study coherent electron dynamics in a biassed undriven ideal semiconductor superlattice coupled to the continuum, near energy level anticrossings. In particular, we examine the dependence of wavepacket dynamical characteristics on electric field detuning, and investigate mixed regimes involving a superposition of energy level anticrossings showing both Rabi oscillations and resonant tunnelling. In earlier work [Phys. Rev. B 75 165421 (2007)], Rabi and Zener resonances were shown to have a common origin, and a criteria for the occurrence of either was proposed. The present results allow a better understanding of the nature of an interminiband resonance, which can be useful in the areas of microwave radiation generation and matter manipulation on the particle level, as well as demonstrate an alternative approach to examining electron level structure of a finite superlattice., Comment: 18 pages, 10 figures, submitted to Phys. Rev. B. submitted to Journal of Physics

Carrier dynamics at energy level anticrossings in biased semiconductor superlattices, was studied in the time domain by solving the time-dependent Schroedinger equation. The resonant nature of interminiband Rabi oscillations has been explicitly demonstrated to arise from interference of intrawell and Bloch oscillations. We also report a simulation of direct Rabi oscillations across three minibands, in the high field regime, due to interaction between three strongly coupled minibands., Comment: 13 pages, 16 figures

The confinement mechanism of electrons in gated circular quantum dots is studied in a sequence of models, from self-consistent 3D Hartree calculations to the semiclassical model of Shikin et al. Separation of the vertical from transverse confinement allows accurate 2D Hartree calculations. For moderate size dots containing $\sim 50$ electrons, 2D Thomas-Fermi can also be accurate. Finally, a Shikin type parameterization of the electron density allows quantitative study of the importance of the many contributions to the confinement potential., Comment: original: 16 pages, 14 figures revision: reduced size to 14 pages, 13 figures

Phonon-assisted tunneling rates are evaluated for a well isolated double dot system defined in a GaAs semiconductor heterostructure of finite thickness. A separable model for the confining potential allows accurate determinations of doublet electron wavefunctions and energies. It is found that at small doublet energies the piezoelectric rates due to flexural modes give the dominant contribution. For small slab thicknesses the predicted rates are up to two orders of magnitude higher than for very thick slabs., Comment: 7 pages, 12 figures, shortened text and corrected typos. 8 pages, 14 figures

Time delay in electron propagation through a finite periodic system such as a semiconductor superlattice is studied by direct numerical solution of the time-dependent Schr\"odinger equation. It is found that addition of an anti-reflection coating significantly reduces the time delay, in addition to increasing the transmissivity., Comment: Version 3: revised sec III b., added appendix and refs. 10 pages, 11 figs. Version 2: major revision, especially pages 5-9; additional references, 9 pages, 11 figures. Version 1 was 7 pages, 11 figures

We discuss the relation between continuum bound states (CBS) localized on a defect, and surface states of a finite periodic system. We use the transfer matrix method to model an experiment of Capasso, and find all continuum bound and anti-bound states. We compute the rate for intra-subband transitions from the ground state to the CBS and derive a sum rule. Finally we show how to improve the confinement of a CBS while keeping the energy fixed., Comment: 6 tables, 13 figures, 19 pages in all

Recent measurements of electron escape from a non-equilibrium charged quantum dot are interpreted within a 2D separable model. The confining potential is derived from 3D self-consistent Poisson-Thomas-Fermi calculations. It is found that the sequence of decay lifetimes provides a sensitive test of the confining potential and its dependence on electron occupation., Comment: 9 pages, 10 figures