We review our experimental study on the electron transport in quantum dots, formed in the two-dimensional electron gas in GaAs/AlGaAs heterostructures. Single electron transport with well-resolved zero-dimensional energy levels is described for both single and coupled quantum dots. Effects of microwave irradiation are also studied, and photon assisted tunneling was observed between two discrete...

We define two laterally gated small quantum dots (∼ 15 electrons) in an Aharonov-Bohm geometry in which the coupling between the two dots can be broadly changed. For weakly coupled quantum dots we find Aharonov-Bohm oscillations. In an intermediate coupling regime we concentrate on the molecular states of the double dot and extract the magnetic field dependence of the coherent coupling.

Organosilane-functionalized carbon dots (SiC-dots) were prepared by a simple one-pot hydrothermal approach. The photoluminescence (PL) properties of the SiC-dots revealed a reversible response toward the temperature (293-343 K). Through Si-O-Si bonding, temperature-sensitive PL SiC-dot films could be easily fabricated on glass substrates.

Newly-synthesized amphiphilic carbon dots were used for spectroscopic analysis and multicolour microscopic imaging of membranes and live cells. We show that Förster resonance energy transfer (FRET) occurred from the amphiphilic carbon dots to different membrane-associated fluorescence acceptors. The amphiphilic carbon dots enabled imaging of membrane disruption by the beta-amyloid peptide.

The self-assembled formation of II-VI Quantum Dots by MBE opens the possibility to develop Quantum Dot Emitters for the green spectral range, which are needed for new, exciting optoelectronic applications. It can be expected that green Quantum Dot laserdiodes will operate already at small threshold currents and with sufficient light power for the use in future Laser-TV systems. Furthermore, II-...

‎we obtain the asymptotic expansion of the sequence with general term $frac{a_n}{g_n}$‎, ‎where $a_n$ and $g_n$ are the arithmetic and geometric means of the numbers $d(1),d(2),dots,d(n)$‎, ‎with $d(n)$ denoting the number of positive divisors of $n$‎. ‎also‎, ‎we obtain some explicit bounds concerning $g_n$ and $frac{a_n}{g_n}$.

Recently, quantum dots have been used as molecular probes substituting for conventional organic fluorophores. Quantum dots are stable against photobleaching and have more controllable emission bands, broader absorption spectra, and higher quantum yields. In this study, an array of ZnS-coated CdSe quantum dots on a slide glass has been prepared by photolithographic method. The array pattern was ...

The inter-sub-level transitions in modulation-doped Ge quantum dots are observed. The dot structure is grown by molecular-beam epitaxy, and consists of 30 periods of Ge quantum dots sandwiched by two 6 nm boron-doped Si layers. An absorption peak in the midinfrared range is observed at room temperature by Fourier transform infrared spectroscopy, which is attributed to the transitions between th...

An asymmetric pair of coupled InAs quantum dots is tuned into resonance by applying an electric field so that a single hole forms a coherent molecular wave function. The optical spectrum shows a rich pattern of level anticrossings and crossings that can be understood as a superposition of charge and spin configurations of the two dots. Coulomb interactions shift the molecular resonance of the o...

As a potential biological imaging probe with a long-wavelength of emission, InP quantum dots were prepared via a high-temperature organic solution approach, and successfully transferred into an aqueous system through a ligand-exchange process using various functional surfactants. Photoluminescence and X-ray characterizations confirmed the desired properties of the InP quantum dots. The cytotoxi...