Optical labels enable visualization and detection of molecules, cells, and tissues. These labels have limited multiplexing capabilities, blink on/off at the single-molecule level, and, in many cases, they have low brightness. We address each of these issues through the development of a sub-50 nm barcoded optical label system by coating fluorescent quantum dots onto the surface of plasmonic nano...

Interaction and correlation effects in quantum dots play a fundamental role in defining both their equilibrium and transport properties. Numerical methods are commonly employed to study such systems. In this paper we investigate the numerical calculation of quantum transport of electrons in spherical centered defect InGaAs/AlGaAs quantum dot (SCDQD). The simulation is based on the imaginary time...

Individual colloidal quantum dots can be optically trapped and manipulated by a single infrared laser beam operated at low laser powers. If the absorption spectrum and the emission wavelength of the trapping laser are appropriately chosen, the trapping laser light can act as a source for two-photon excitation of the trapped quantum dot. This eliminates the need for an additional excitation lase...

In this article, the temperature behavior of output power of superluminescent light-emitting diode (SLED) by considering the effect of non-radiative recombination coefficient, non-radiative spontaneous emission coefficient and Auger recombination coefficients has been investigated. For this aim, GaN pyramidal quantum dots were used as the active region. The numerical method has been used to sol...

We review progress on the spintronics proposal for quantum computing where the quantum bits (qubits) are implemented with electron spins. We calculate the exchange interaction of coupled quantum dots and present experiments, where the exchange coupling is measured via transport. Then, experiments on single spins on dots are described, where long spin relaxation times, on the order of a millisec...

We study the two-qubit controlled-not gate operating on qubits encoded in the spin state of a pair of electrons in a double quantum dot. We assume that the electrons can tunnel between the two quantum dots encoding a single qubit, while tunneling between the quantum dots that belong to different qubits is forbidden. Therefore, the two qubits interact exclusively through the direct Coulomb repul...

The photoexcitation energy transfer is found and investigated in complexes of CdSe/ZnS cationic quantum dots and chlorin e6 molecules formed by covalent bonding and electrostatic interaction in aqueous solution and in porous track membranes. The quantum dots and chlorin e6 molecules form stable complexes that exhibit Förster resonance energy transfer (FRET) from quantum dots to chlorin e6 regar...

We present an optical study of two closely stacked self-assembled InAs/GaAs quantum dots. The energy spectrum and correlations between photons subsequently emitted from a single pair provide not only clear evidence of coupling between the quantum dots but also insight into the coupling mechanism. Our results are in agreement with recent theories predicting that tunneling is largely suppressed b...

The absorption cross section of colloidal quantum dots in close-packed monolayers shows a 4 (CdSe) to 5-fold (PbS) enhancement compared to quantum dots in a dilute dispersion. Quantitative agreement is demonstrated between the value and the size dependence of the enhancement and theoretical model predictions based on dipolar coupling between neighboring quantum dots. This collective optical beh...

Quantum dots laser diodes using the dots-in-a-well (DWELL) structure (InAs dots in an InGaAs quantum wells) have exhibited significant recent progress. With a single InAs dot layer in Inoi5Gao.8sAs quantum well, threshold current densities are as low as 26 A cm2 at 1 .25 xm. Quantum dot laser threshold current densities are now lower than any other reported semiconductor laser. In this work, th...