Showing papers in "Superlattices and Microstructures in 1998"

TL;DR: In this paper, the authors provide a review of the Landauer-Bruggeman effective medium approximation as applied to random composite media, i.e., materials in which there is a linear relation between a curl-free electric field and a divergence-free current density.

TL;DR: In this paper, the authors discuss how quantum entanglement is the key to protecting quantum states from decoherence in a manner which, in a theoretical sense, is as effective as the protection of digital data from bit noise.

TL;DR: In this article, a universal heat conductance expression that depends on the properties of the conducting pathway only through the mode cutoff frequencies is derived, and corrections due to reflections at the junction between the thermal body and the conducting bridge are found to be small except at very low temperatures where only the lowest few bridge modes are excited.

TL;DR: In this paper, the authors draw attention to the new insights and perspectives that the transmission viewpoint can provide into the design of deep submicron MOSFETs and show that the saturation drain current is determined by the transmission coefficient which depends sensitively on the electric field within a mean free path of the source.

TL;DR: In this article, the temperature dependence of photoluminescence properties of a number of InAs/GaAs heterostructures with InAs layer thickness ranging from 0.5 monolayer (ML) to 3 ML, indicating spontaneous formation of quantum dots (QDs).

TL;DR: In this paper, the effect of the elctron's Fermi statistics on shot noise is discussed and shot noise as a tool for charge measurements is discussed as well as the properties of shot noise in systems of various sizes from mesoscopic, ballistic and classical diffusive conductors.

TL;DR: In this paper, the authors describe a kinetic approach based on a master equation for modelling the injection and ejection of electrons into and from the quantum dot, and compare numerical results with experimental results for the silicon/silicon dioxide system where such memory structures have been achieved.

TL;DR: In this paper, the concept and formalization of the arrival time in quantum mechanics are discussed and different approaches based on trajectories, quantization rules, time operators, phase-space techniques, renewal equations or operational procedures are reviewed or proposed.

TL;DR: In this paper, the authors set up a calculation for the ground-state binding energy of an on-center hydrogenic impurity in the simultaneous presence of intense high-frequency laser and static electric fields.

TL;DR: In this article, Raman-scattering results for CdTe nanocrystals in doped glasses are presented, which clearly show the confinement effects on the phonon spectra as a function of the quantum-dot size.

TL;DR: In this article, two different proposals for implementing reversible and dissipationless logic innanoelectronics systems are described, which use interacting single electrons housed in quantum dots to elicit logic functions.

TL;DR: In this article, a self-organized, position-controlled and parallel growth of GaAs and InAs nanowiskers is successfully demonstrated by using a metal-organic chemical vapour deposition method.

TL;DR: In this paper, a simple variational wave function is proposed for calculating the ground-state energy of a hydrogenic donor located at the centre of a spherical parabolic quantum dot, and binding energies are calculated for three values of the parameter which gives the strength of the confining parabolic potential by the proposed wave function as well as by a wavefunction used by Xiao et al.

TL;DR: In this article, it was shown that the zero-temperature limit of the distribution of the thermopower of a one-dimensional disordered wire in the localized regime is a Lorentzian, with a disorder-independent width of 4π3kB2T/3eΔ (whereTis the temperature and Δ the mean level spacing).

TL;DR: In this paper, the authors investigate the time evolution of waves in evanescent media generated by a source within this medium and observed at some distance away from the location of the source.

TL;DR: In this article, a scattering theory calculation for the potential distribution and the associated currentvoltage characteristic in a ballistic quantum point contact is presented, where the electric field is finite only near the entrance to or exit from the constriction, while no potential drop occurs in the device itself.

TL;DR: In this article, an experimental demonstration of Bloch oscillations connected with Bragg reflection of electrons from the first miniband edge in superlattices of different silicon carbide polytypes was discussed.

TL;DR: In this paper, the magnetic loops of a hard superconductor are calculated analytically and the analytical representation of the results is given in a relationship with the magnetic flux distribution inside a sample in the mixed state of superconductivity.

TL;DR: In this paper, it was shown that the zero-temperature limit of the distribution of the thermopower of a one-dimensional disordered wire in the localized regime is a Lorentzian, with a disorder-independent width of 4π3kB2T/3eΔ (whereTis the temperature and Δ the mean level spacing).

TL;DR: In this paper, a theory of long-range exchange interaction between an electron and a hole in a zero-dimensional exciton has been developed taking into account the retardation effect.

TL;DR: In this paper, the potential of electron waveguides in photonic applications, with emphasis on far-infrared (or THz) photodetectors, has been investigated.

TL;DR: This paper addresses foundational issues related to quantum computing by describing quantum robots as mobile quantum systems with on-board quantum computers that interact with environments.

TL;DR: The positively and negatively charged excitons, X + and X −, respectively, were identified by their magnetic circular dichroism in the absorption spectra of modulation-doped CdTe/Cd 0.69 Mg 0.23 Zn 0.08 Te multiple quantum wells at small carrier densities (≈10 10 cm −2 ).

TL;DR: In this paper, the condition for a direct band gap in Si quantum wires is investigated within the effective mass theory for wires coherent in every direction perpendicular to the wire direction, and the condition is calculated using the equivalent condition that the minimum energy of the one-dimensional subbands of electrons is at the Γ-point, because holes always have a minimum energy at this point.

TL;DR: In this paper, the use of an atomic force microscope (AFM) as a nanolithographic tool is demonstrated, where a photoresist layer several nanometre thin is indented by the vibrating AFM tip, where software control switches the tapping force from the imaging to the patterning mode.

TL;DR: In this article, the magnetisation properties of individual superconducting particles with size down to 0.1 micron were investigated using submicron Hall probes, which detect a local magnetic field and work effectively as micro-fluxmeters similar to, e.g., SQUIDs, with an effective detection loop of only about a square micron.

TL;DR: Au clusters were formed on the GaAs(111)B substrate by the field evaporation of Au atoms using an atomic force microscope (AFM) as discussed by the authors, and the obtained clusters appeared as mounds with typical diameters of 100-150 nm and heights of 1.5 nm.

TL;DR: In this paper, the critical design issues for unipolar silicon quantum-well inter-subband lasers are investigated for surface-emitting and edge-emiting geometries.

TL;DR: In this article, the authors presented high-temperature (77 K, 300 K) single-hole n+−p+n transistors based on silicon diffusion nanostructures.

TL;DR: In this article, the bipolaron binding energy and effective mass in cylindrical and planar quantum wires with "parabolic" confinement were calculated within the framework of the Feynman variational method and an analogy was found between the effects due to strong confinement and those due to the application of a strong magnetic field.