Quantum-wire and quantum-box structures for narrow-gap materials with small effective masses, such as HgCdTe, can readily be fabricated using current lithographic techniques. In this article, we calculate the Auger-recombination carrier lifetimes in HgCdTe quantumwire and quantum-box structures, with band gaps in the 2-5 ,um wavelength range. Quantum confinement is generally believed to increas...

We propose an on-demand single-photon source for quantum cryptography using a metal–insulator–semiconductor quantum dot capacitor structure. The main component in the semiconductor is a p-doped quantum well, and the cylindrical gate under consideration is only nanometres in diameter. As in conventional metal–insulator–semiconductor capacitors, our system can also be biased into the inversion re...

A potential implementation of quantum-computation schemes in semiconductor-based structures is proposed. In particular, an array of quantum dots is shown to be an ideal quantum register for a noiseless information encoding. In addition to the suppression of phase-breaking processes in quantum dots due to the well-known phonon bottleneck, we show that a proper quantum encoding allows to realise ...

Aalto University, P.O. Box 11000, FI-00076 Aalto www.aalto.fi Author Osmo Vänskä Name of the doctoral dissertation Theoretical studies of optical transitions in semiconductor quantum structures Publisher School of Electrical Engineering Unit Department of Microand Nanosciences Series Aalto University publication series DOCTORAL DISSERTATIONS 214/2014 Field of research Electrophysics Manuscript ...

Very low threshold currents ~,100 mA! have been achieved in InGaAs strained single quantum well lasers at cryogenic temperatures. Threshold currents of 38 and 56 mA and external quantum efficiency ;1 mW/mA have been demonstrated under cw operation condition at temperatures of 6 and 77 K, respectively. The external quantum efficiency increased by about a factor of 2 at low temperatures ~,100 K! ...

Recent advances in thin-film crystal-g:rowth techniques such as molecular-beam epitaxy (MBE) have enabled the fabrication of quantum-well devices, which consist of alternating layers of various crystalline solid materials so thin that the materials' combined quantum-mechanical properties override their individual bulk properties. By using MBE, we constructed a number of quantum-well devices tha...

We have generated picosecond opfic1 pulses with very pure spectral characteristics using semiconductor lasers with monolithic cavities. Fx repetition rates less than 10 GHz, gain-switching of DFB lasers with quantum well loss-gratings is usul. Monolithic colliding pulse mode-locked semiconductor lasers are used to generate short pulses with repetition rate up to 350GHz.

Interband mixing between two-dimensional states localized in a surface quantum well and heavy hole states of the valence band in narrow gap semiconductor Abstract Theoretical calculations in the framework of Kane model have been carried out in order to elucidate the role of interband mixing in forming the energy spectrum of two-dimensional carriers, localized in a surface quantum well in narrow...