Opto-electronic properties of single-walled carbon nanotubes can be significantly modified by chromophore confinement into their hollow core. This study deals with quaterthiophene derivatives encapsulated into nanotubes displaying different diameter distributions. We report a significant electron transfer from the confined molecules to the nanotubes in our hybrid systems, evidenced by photoluminescence and Raman investigations. This charge transfer leads to an important enhancement of the photoluminescence intensity by a factor of nearly five depending on the tube diameter. Energy shifts observed on both absorption and emission on the hybrid system also depend on the nanotube diameters and are interpreted in terms of local structure of the confined molecules. The Raman G-band of hybrid systems exhibits a drop in intensity and significant shifts whose magnitude and direction strongly depend on the nanotube diameter. These behaviors are consistent with a weak electron transfer from the molecule to the tube, in good agreement with the PL analysis. In addition, close to the molecule resonance, the magnitude of the G-band shifts are modified and the intensity loss is amplified, strongly suggesting a photo-induced electron transfer. Finally, the Breit-Wigner-Fano lineshape (characteristic of electron-phonon coupling) of the Raman G-band is strongly reduced for defective metallic nanotubes. After molecule functionalization, this peculiar profile is recovered, suggesting a back donation of electrons to the nanotube. Thus, confinement species into nanotubes allow moving the Fermi level and consequently to monitor their opto-electronic properties.

We discuss two procedures to obtain empirical potentials from ab initio trajectories. The first methodconsists in adjusting the parameters of an empirical pair potential so that the radial distribution functionsextracted from classical simulations using this potential match the ones extracted from the ab initio sim-ulations. As a case study, we consider the example of amorphous silica, a material that is highly relevantin the field of glass science as well as in geology. With our approach we are able to obtain an empiricalpotential that gives a better description with respect to structural and thermodynamic properties thanthe potential proposed by van Beest, Kramer, and van Santen, and that has been very frequently usedas a model for amorphous silica. The second method is the so-called ‘‘force matching” approach proposedby Ercolessi and Adams to obtain an empirical potential. We demonstrate that for the case of silica thismethod does not yield a reliable potential and discuss the likely origin for this failure.

The book presents the future developments and innovations in the developing field of microelectronics. The book’s chapters contain contributions from various authors, all of whom are leading industry professionals affiliated either with top universities, major semiconductor companies, or government laboratories, discussing the evolution of their profession. A wide range of microelectronic-related fields are examined, including solid-state electronics, material science, optoelectronics, bioelectronics, and renewable energies. The topics covered range from fundamental physical principles, materials and device technologies, and major new market opportunities.

NMR spectroscopy has been established as a potent method for the detn. of foldamer structures in soln. However, the NMR techniques could be limited by averaging, so addnl. exptl. techniques are often needed to fully endorse the folding properties of a sequence. The authors have recently demonstrated that oligo-​γ-​peptides composed of 4-​amino(methyl)​-​1,​3-​thiazole-​5-​carboxylic acids (ATCs) adopt an original helical fold stabilized by hydrogen bonds forming C9 pseudocycles. The main objective of the present work is to restudy the folding of ATC oligomer 1 to identify reliable FTIR and NMR structural markers that are of value for tracking the degree of organization of ATC-​based peptides.

We demonstrate high-spatial resolution imaging of localized cavity modes through third-harmonic frequency conversion. The experiments are performed with a III-nitrideon-silicon photonic platform. The resonant cavities are formed within suspended two-dimensional photonic crystals and are excited with a continuous-wave excitation around 1550 nm. The III-nitride materials (GaN and AlN) are transparent for both pump and harmonics. The third-harmonic nonlinear process allows one to indirectly observe the fundamental confined cavity mode with spatial profiles equivalent to those usually obtained by local probe microscopy techniques such as scanning near-field optical microscopy. An excellent agreement is obtained between the measured polarization-resolved third harmonic emission patterns and those calculated through the third-order nonlinear polarization. We show that the spatial profiles of the radiated patterns are strongly dependent on defocusing, thus highlighting the strong sensitivity of the imaging.

We review the recent developments of the polariton physics in microcavities featuring the exciton-photon strong coupling at room-temperature, and leading to the achievement of room-temperature polariton condensates. Such cavities embed active layers with robust excitons that present a large binding energy and a large oscillator strength, i.e. wide bandgap inorganic or organic semiconductors, or organic molecules. These various systems are compared, in terms of figures of merit and of common features related to their strong oscillator strength. The various demonstrations of polariton laser are compared, as well as their condensation phase diagrams. The room-temperature operation indeed allows a detailed investigation of the thermodynamic and out-of-equilibrium regimes of the condensation process. The crucial role of the spatial dynamics of the condensate formation is discussed, as well as the debated issue of the mechanism of stimulated relaxation from the reservoir to the condensate under non-resonant excitation. Finally the prospects of polariton devices are presented.

We report on magnetospectroscopy of HgTe quantum wells in magnetic fields up to 45 T in a temperature range from 4.2 up to 185 K. We observe intra- and inter-band transitions from zero-mode Landau levels, which split from the bottom conduction and upper valence sub-bands and merge under the applied magnetic field. To describe experimental results, realistic temperature-dependent calculations of Landau levels have been performed. We show that although our samples are topological insulators at low temperatures only, the signature of such a phase persists in optical transitions at high temperatures and high magnetic fields. Our results demonstrate that temperature-dependent magnetospectroscopy is a powerful tool to discriminate trivial and topological insulator phases in HgTe quantum wells.