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

/pdf/prospects-of-colloidal-nanocrystals-for-electronic-and-3dxpyhl3r7.pdf

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

Summary form only given. We present time resolved pump and probe measurements, in the strong excitation regime, of a semiconductor microcavity (MC) containing quantum wells (QWs). The fundamental QW exciton (X) and the cavity mode were resonant or slightly detuned, while the energy of the laser photons was chosen to be dose to the energy of the photon like polariton. The investigated MCs are high finesse heterostructures made of GaAs/GaAlAs layers, featuring cavity-mode line widths of at most 0.7 meV. The GaAs spacer layer contains one or several InGaAs QWs positioned at the anti-nodes of the electric field. At low excitation densities, the X-cavity system is in the strong coupling regime. The X level is more or less inhomogeneously broadened, its width varies between five and a few tenths of meV. The measurements were done at near normal incidence, using 100 fs long laser pulses. Pump-probe delays /spl Delta/t close to zero were chosen, for which the X-photon system inside the cavity is coherent. The transmitted and reflected intensities of the probe vs wavelength, pump intensity and pump-probe delay have been measured.

Features of strong coherent excitation of microcavities containing quantum wells

Crossover from exciton to biexciton cavity polaritons

Summary form only given. The importance of LO phonon emission for intersubband scattering (ISBS) processes is now well established. In very good agreement with theoretical expectations, such a process gives scattering times of 1 ps or less. The situation is different in wide quantum wells, when the energy separation /spl Delta/E/sub 12/ between the first two subbands is smaller than /spl planck//spl omega//sub LO/. It has often been proposed that ISBS should then be mediated mainly by acoustical phonons, and be quite slow. Such wells would then be promising for laser applications. However, the demonstration of such a laser failed to be obtained. An explanation was in fact proposed in 1989 by Goodnick and Lugli who computed carrier-carrier induced intersubband scattering. It is clear from their calculations that such ISBS could be as short as a few ps, 100 times faster than acoustic phonons. A number of results have nevertheless been published since then, with scattering times ranging from 1 ps to 1 ns. We have carefully studied ISBS by using femtosecond time-resolved luminescence with resonant excitation. The advantage of luminescence in addition to the very good time resolution is the ability to probe the whole distribution of electrons. This of course needs some assumptions on the behavior of holes, but we can show that their contribution to the observed dynamics is minimal.

Carrier-carrier contribution to intersubband scattering in wide quantum wells

Ecole Polytechnique Fdrale de Lausanne, EPFL, CH-1015 Lausanne, SwitzerlandReceived 15 September 2003, accepted 18 September 2003Published online 2 February 2004PACS 73.21.Fg, 78.47.+p, 78.55.Cr, 78.67.DeWe present an experimental study of the properties of a dense electron–hole plasma in GaAs/AlGaAsquantum wells. A high spatial resolution Photoluminescence setup including spectral and temporal ana-lysis has been developed to test the possibility of collective emission from an electron-hole plasma.

Imaging of spontaneous and stimulated emission from high-density plasmas in quantum wells

The luminescence excitation spectra of GaAs/GaAlAs superlattices show new structures when their period is such that the miniband width for electrons is of the order of 10 meV. The experimental spectra are remarkably reproduced by theoretical calculations, and we are then able to give an assignement to these structures. In particular, new excitonic transitions are observed which might be the equivalent of saddle-point excitons. We have performed excitation studies under magnetic field in both Faraday and Voigt configurations in order to check the different attributions. Confirmation of the excitonic character of the new peaks is obtained. When the superlattice period decreases, the exciton binding energy is observed to decrease and the miniband width to increase.

Benoit Deveaud

Papers

Features of strong coherent excitation of microcavities containing quantum wells

Crossover from exciton to biexciton cavity polaritons

Carrier-carrier contribution to intersubband scattering in wide quantum wells

Imaging of spontaneous and stimulated emission from high-density plasmas in quantum wells

Magneto-Optical Study of Miniband Dispersion and Excitonic Effects in GaAs/GaAlAs Superlattices