We present a comprehensive, up-to-date compilation of band parameters for the technologically important III–V zinc blende and wurtzite compound semiconductors: GaAs, GaSb, GaP, GaN, AlAs, AlSb, AlP, AlN, InAs, InSb, InP, and InN, along with their ternary and quaternary alloys. Based on a review of the existing literature, complete and consistent parameter sets are given for all materials. Emphasizing the quantities required for band structure calculations, we tabulate the direct and indirect energy gaps, spin-orbit, and crystal-field splittings, alloy bowing parameters, effective masses for electrons, heavy, light, and split-off holes, Luttinger parameters, interband momentum matrix elements, and deformation potentials, including temperature and alloy-composition dependences where available. Heterostructure band offsets are also given, on an absolute scale that allows any material to be aligned relative to any other.

Band parameters for III–V compound semiconductors and their alloys

Nanocrystals (NCs) discussed in this Review are tiny crystals of metals, semiconductors, and magnetic material consisting of hundreds to a few thousand atoms each. Their size ranges from 2-3 to about 20 nm. What is special about this size regime that placed NCs among the hottest research topics of the last decades? The quantum mechanical coupling * To whom correspondence should be addressed. E-mail: dvtalapin@uchicago.edu. † The University of Chicago. ‡ Argonne National Lab. Chem. Rev. 2010, 110, 389–458 389

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Prospects of Colloidal Nanocrystals for Electronic and Optoelectronic Applications

Bose-Einstein condensation (BEC) has been observed in a dilute gas of sodium atoms. A Bose-Einstein condensate consists of a macroscopic population of the ground state of the system, and is a coherent state of matter. In an ideal gas, this phase transition is purely quantum-statistical. The study of BEC in weakly interacting systems which can be controlled and observed with precision holds the promise of revealing new macroscopic quantum phenomena that can be understood from first principles.

Bose-Einstein condensation in a gas of sodium atoms

Topological photonics is a rapidly emerging field of research in which geometrical and topological ideas are exploited to design and control the behavior of light. Drawing inspiration from the discovery of the quantum Hall effects and topological insulators in condensed matter, recent advances have shown how to engineer analogous effects also for photons, leading to remarkable phenomena such as the robust unidirectional propagation of light, which hold great promise for applications. Thanks to the flexibility and diversity of photonics systems, this field is also opening up new opportunities to realize exotic topological models and to probe and exploit topological effects in new ways. This article reviews experimental and theoretical developments in topological photonics across a wide range of experimental platforms, including photonic crystals, waveguides, metamaterials, cavities, optomechanics, silicon photonics, and circuit QED. A discussion of how changing the dimensionality and symmetries of photonics systems has allowed for the realization of different topological phases is offered, and progress in understanding the interplay of topology with non-Hermitian effects, such as dissipation, is reviewed. As an exciting perspective, topological photonics can be combined with optical nonlinearities, leading toward new collective phenomena and novel strongly correlated states of light, such as an analog of the fractional quantum Hall effect.

Topological Photonics

日本物理学会誌及びJournal of the Physical Society of Japanの月刊について

Time resolved luminescence measurements under resonant excitation were performed at 10 K on the free exciton in very high quality GaAs-AlAs quantum wells. At resonance, the luminescence intensity is increased by two orders of magnitude, and the decay is short. The radiative lifetime of the excitons in the radiant states is about 18 ps in agreement with the theory of Hanamura and Andreani. The lifetime of the thermalized excitons is about 80 ps at low excitation and it increases with the excitation density.

/pdf/lifetime-of-excitons-in-gaas-quantum-wells-1op9rmkjis.pdf

Lifetime of excitons in GaAs quantum wells

Picosecond and subpicosecond luminescence techniques have been used to study vertical transport in GaAs/GaAIAs superlattices. The great advantages of these techniques are the very good time resolution and the absence of processing of the sample. We describe in this revue the main results and emphasize on some of the interesting aspects of the interpretation of the results. Both electron and hole mobilities can be obtained by using different excitation densities. They are compared with theoretical estimates.

Centre National D'Etudes des Telecommunications Lannion, France

A SNOM apparatus working at liquid-He temperatures has been realized and characterized. Standard optical facilities allow for a combined spatial and spectral analysis of the photoluminescence emissions in semiconductors. A novel distance control system is used. The sensitivity in the approach direction is 0.2 nm, and quality factors up to 2850 have been obtained. No electronic components are needed close to the sensor, allowing to employ it in a liquid He environment. The system is extremely compact and allows for several hours stability at 5 K.

Novel Tuning Fork Sensor for Low-Temperature Near-Field Spectroscopy

The dynamics of carrier capture and intersubband relaxation in GaAs quantum well have been measured, using a time-resolved photoluminescence technique. At low carrier densities (≤ 2×1010 cm -2), electron capture times are shown to oscillate as a function of well width and a quantum-mechanical resonance is observed when one confined level is 36 meV below the barrier edge. Holes capture times are fast (< 10 ps), and depend weakly on the structure. No significant changes of the carrier capture times are observed for carrier densities up to 1×1011 cm-2. For well widths < 150 A, a fast intersubband (2→ 1) relaxation time (of typically 3 ps) is measured. This relaxation time is shown to increase by an order of magnitude at longer well width (220 A). The observed variation of both the electron capture times and the intersubband relaxation times with well width, demonstrate the importance of LO phonon quantum-mechanical scattering processes.

Ultrafast Dynamics of Electronic Capture and Intersubband Relaxation in GaAs Quantum Well

get a bener understanding o f the fundamental physical processes involved in l h e interaction between a short optical pulse and a high density plasma. So far, the uluafast pain dynamics i n SOA's has been mainly studied by means of standard pump and probe (PBrP) measurements in which the wavelengths o f the pump and probe are identical. Here, we present a new experimental technique which is an ulwfast cross-gain modulation (XGM) behveen a I50 fa pump pulse and a weak cw probe signal. The advantages of the XGM o v a the P&P technique are two-fold. Firstly, the probe wavelength can be varied and therefore the gain recovery at different wavelengths around the pump wavelength can be obtained. Secondly, the probe sigoal i s a cw signal, thus having a very narrow linewidth and hence a high spectral resolution. Consequently, information is obtained on the spectral carrier population distributioo and ita

http://ieeexplore.ieee.org/iel5/5829/15540/00719066.pdf

Benoit Deveaud

Papers

Lifetime of excitons in GaAs quantum wells

Centre National D'Etudes des Telecommunications Lannion, France

Novel Tuning Fork Sensor for Low-Temperature Near-Field Spectroscopy

Ultrafast Dynamics of Electronic Capture and Intersubband Relaxation in GaAs Quantum Well

150 fs Cross-Gain Modulation Experiments on Semiconductor Optical Amplifiers