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Fano-like quantum routing of single photons in a system with two waveguides coupled to two collocated atoms is investigated theoretically. Using a full quantum theory in real space, photonic scattering amplitudes along four ports of the waveguide network are analytically obtained. It is shown that, by adjusting the atomic dipole-dipole interaction, an evident Fano-line shape emerges in the scattering spectra of the single-dot configuration system. Moreover, Fano resonance can also be achieved by varying the atom-waveguide coupling strength and atomic detuning, in the presence of the atomic dipole-dipole interaction. Therefore, the atomic dipole-dipole interaction may be utilized as a possible way to control spectral Fano-like resonance. The feasibility with the experimental waveguide channels is also discussed.

An InGaN multiple-quantum-well (MQW) violet-light-emitting diode (LED) is grown by low-pressure metalorganic chemical vapour deposition. It is found that photoluminescence wavelength of the InGaN MQW violet LED is lengthened with increasing growth temperature and with the increasing trimethylindium flow of the InGaN wells. The electroluminescence peak wavelength of the violet LED are about 401 nm with full width at half maximum of 14 nm, and the output power in injection current of 20 mA at room temperature is 4.1 mW.

The near-ultraviolet lighting-emitting-diodes (UV-LEDs) with the InGaN/GaN multi-quantum-well (MQW) structure were grown by low-pressure metalorganic vapour phase epitaxy. The double crystal x-ray diffraction revealed a distinct second-order satellite peak. The near-ultraviolet InGaN/GaN MQW LEDs have been successfully fabricated to emit at 401.2 nm with narrow FWHM of 14.3 nm and the forward voltage of 3.6 V at 20 mA injection current at room temperature. With increasing forward current from 10 mA to 50 mA, the redshift of the peak wavelength was observed due to the band-gap narrowing caused by heat generation.

Optical storage caused by photo-induced anisotropy in poly[3'-methyl-4'-bis(N,N-oxyethylene)imino-4-nitro-azobenzene sebacoyl] film is studied by degenerate four-wave mixing. Molecule orientation gratings which are stable for three months are produced. The grating in the sample can be "erased" by using circular polarized light. So an azobenzene polymer thin film can be used many times to restore optical information.

Room-temperature negative differential resistance (NDR) characteristics are observed in a nanocrystalline Si quantum dot (nc-Si QD) floating-gate MOS structure, which is fabricated by plasma-enhanced chemical vapor deposition. Clear multi-NDR peaks for the electrons and holes, shown in the I—V curves, which are significant for the application of multiple value memory and logic, are proved to be induced by electron and hole resonant tunneling into the nc-Si QDs from the substrate. The calculation results indicate that these NDR characteristics should be associated with the Coulomb blockade effect and the quantum confinement effect of the nc-Si QDs. Furthermore, low-temperature I—V characteristics are also investigated to confirm the room-temperature results.

The effects of dopants on the defects of GaN films were investigated by using different methods, such as wet, etching of pits, x-ray diffraction and photoluminescence (PL). Three kinds of the samples were prepared with different dopants, that is, nominally undoped, Si-doped and Mg-doped GaN films. It was found that the lowest density of the, etched pit was existed in the nominally undoped GaN, while the highest in the Mg-doped sample. The effects of the dopants on the, etching pits were discussed.

The first law of thermodynamics for the three horizons of Reissner—Nordstrom quintessence (RNQ) spacetime is obtained. For a general process of RNQ spacetime, the expressions for the radius changes of the three horizons are derived. When only mass changes, the heat fluxes through the three horizons are equivalent and no heat is left in the black hole region. Finally, a further discussion on the thermal properties of an RNQ black hole is given.

A nonvolatile memory device with nitrided Si nanocrystals embedded in a Boating gate was fabricated. The uniform Si nanocrystals with high density (3 × 1011 cm−2) were deposited on ultra-thin tunnel oxide layer (~ 3 nm) and followed by a nitridation treatment in ammonia to form a thin silicon nitride layer on the surface of nanocrystals. A memory window of 2.4 V was obtained and it would be larger than 1.3 V after ten years from the extrapolated retention data. The results can be explained by the nitrogen passivation of the surface traps of Si nanocrystals, which slows the charge loss rate.

Nanowire devices with back gate are fabricated in a heavy doped ultra thin SOI layer by electron beam lithography. Regular and periodic Coulomb oscillations with single dot behavior are observed in an appropriate back gate voltage range. The oscillation period can be determined by the back gate capacitance. The role of the back gate can control the electrical characteristics from the multi-dot junction regimes to the single dot junction regimes. These Coulomb oscillations due to single-electron tunneling are not smeared out by thermal vibration energy when the temperature is less than 40 K.

InAlN/GaN heterojunction structures are grown on two-inch c-face(0001) sapphire substrates by metalorganic chemical vapour deposition. AlN and AlGaN interlayers are intentionally inserted into the structure to improve the electrical properties. The lowest sheet resistance of 359Ω/sq and the highest room-temperature two-dimensional electron gas (2DEG) mobility of 1051 cm2 V−1s−1 is obtained in the structure with AlN thickness of 1.3 nm. The structure with AlN thickness of 2 nm exhibits the highest 2DEG concentration of 1.84 × 1013 cm−2. The sample with an AlGaN interlayer gives a smoother surface morphology compared to the one using an AlN interlayer, indicating potential applications of this technique in device fabrication.

The nanocrystal-Si quantum dot (nc-Si QD) floating gate MOS structure is fabricated by using plasma-enhanced chemical vapour deposition (PECVD) and furnace oxidation technology. The capacitance hysteresis in capacitance-voltage (C – V) measurements confirm the charging effect of nc-Si QDs. Asymmetric charging current peaks both for electrons and holes have been observed in current-voltage (I – V) measurements at room temperature for the first time. The characteristic and the origin of these current peaks in this nc-Si QD MOS structure is investigated systematically. Moreover, the charge density (10−7 C/cm2) calculated from the charging current peaks in the I – V measurements at different sweep rates shows that each quantum dot is charged by one carrier. The difference of charging threshold voltages between the electrons and holes charging peaks, ΔVG, can be explained by the quantum confinement effect of the nc-Si dots in size of about 3.5 nm.