Asymmetric 2D photonic crystals were fabricated using polymer embedded PbS quantum dots on plastic substrates for enhancing optical down conversion efficiency from blue to near infrared wavelengths through enhanced extraction and excitation effects. We demonstrate 8x improvement of QD emission at normal incidence extraction from enhanced extraction and 2.5x improvement in power conversion effic...

a noninteracting quantum-dot arrays side coupled to a quantum wire is studied. transport through the quantum wire is investigated by using a noninteracting anderson tunneling hamiltonian. the conductance at zero temperature develops an oscillating band with resonances and antiresonances due to constructive and destructive interference in the ballistic channel, respectively. moreover, we have fo...

application of quantum-dot is a promising technology for implementing digital systems at nano-scale.  quantum-dot cellular automata (qca) is a system with low power consumption and a potentially high density and regularity. also, qca supports the new devices with nanotechnology architecture. this technique works based on electron interactions inside quantum-dots leading to emergence of quantum ...

we will present a detailed investigation of intersubband transitions process in core-multi shells quantum dots. the confined wave functions and eigenenergies of electrons in quantum dots have been calculated under the effective-mass approximation by solving a three-dimensional schrodinger equation. excellent dependence is found between size effects, time relaxation and degenerate four wave mixi...

We study the transport properties of two double quantum dots in a parallel arrangement at temperatures of a few kelvin. Thereby, we show that decoherence entailed by the substrate phonons affects the shot noise. For asymmetric coupling between the dots and the respective lead, the current noise is sub-Poissonian for resonant tunneling, but super-Poissonian in the vicinity of the resonances. Our...

We propose an implementation of a quantum controlledNOT gate on the basis of dipole-dipole interacting asymmetric quantum dots. Our implementation does not require application of an external electric field as the one proposed earlier [Barenco et. al, Phys. Rev. Lett., 74, 4083 (1995)]. Results of our numerical simulations show that owing to the dot asymmetricity, the coupling constant of the di...

In this work-the second of a pair of articles-we consider transport through spatially symmetric quantum dots with leads whose widths or positions do not obey the spatial symmetry. We use the semiclassical theory of transport to find the symmetry-induced contributions to weak localization corrections and universal conductance fluctuations for dots with left-right, up-down, inversion, and fourfol...

The influence of high-frequency fields on quantum transport through a quantum dot is studied in the low-temperature regime. We generalize the non crossing approximation for the infinite-U Anderson model to the timedependent case. The dc spectral density shows asymmetric Kondo side peaks due to photon-assisted resonant tunneling. As a consequence we predict an electron-photon pump at zero bias w...