We have succeeded in generating highly charged excitons in InAs self-assembled quantum dots by embedding the dots in a field-effect heterostructure. We discover an excitonic Coulomb blockage: over large regions of gate voltage, the exciton charge remains constant. We present here a summary of the emission properties of the charged excitons. INTRODUCTION An exciton is the elementary excitation i...

Coherent coupling and formation of molecular orbitals in vertically coupled quantum-dot molecules is studied for a seven-dot InAs/GaAs system. The electron states are computed using a nanoelectronic modelling tool NEMO-3D. The tool optimizes atomic positions in the sample with up to 64 million atoms in the frame of the atomistic VFF model. The resulting optimal interatomic distances are then us...

Both single electron and hole quantum dot transistors in silicon-on-insulator were fabricated and characterized. The quantum dots were formed using electron-beam nanolithography and reactive ion etching. The single electron quantum dot transistors show the oscillation of the drain current as a function of the gate voltage at temperatures up to 170 K and drain biases up to 80 mV. The oscillation...

The dynamical response of InAs/GaAs quantum-dot microdisk lasers has been experimentally investigated using femtosecond optical pumping. Because surface recombination and carrier diffusion are suppressed in the quantum dots, the response speed of a quantum-dot microdisk laser is much faster than that of a quantum-well microdisk laser. A turn-on time as short as 7.8 ps has been achieved in a qua...

Semiconductor quantum dot superlattices consisting of arrays of quantum dots have shown great promise for a variety of device applications, including thermoelectric power generation and cooling. In this paper we theoretically investigate the effect of long-range order in a quantum dot array on its in-plane lattice thermal conductivity. It is demonstrated that the long-range order in a quantum d...

Within the last few years, quantum computation has developed into a truly interdisciplinary field involving the contributions of physicists, engineers, and computer scientists. There have been several experimental studies in order to find the proper physical realization of qubits to perform quantum computation. One of the most promising candidates for qubits is the spin state of the electrons, ...

Quantum-dot Cellular Automata (QCA) has low power consumption and high density and regularity. QCA widely supports the new devices designed for nanotechnology. Application of QCA technology as an alternative method for CMOS technology on nano-scale shows a promising future. This paper presents successful designing, layout and analysis of Multiplexer with a new structure in QCA technique. In thi...

A study of the [C6 H6 Ir(PH3 )3 ]+ iridatropylium cation structure based on frontier orbital analysis, thermodynamic analysis, and natural bond orbital (NBO) theory is the main aim of the present research. Also, HOMO, LUMO energies, hardness, electrophilicity and chemical potential were calculated. Structural analysis indicated the optimized geometry shows a good agreement with the experimental...