Unpolarized states and hidden polarization

We capitalize on a multipolar expansion of the polarisation density matrix, in which multipoles appear as successive moments of the Stokes variables. When all the multipoles up to a given order $K$ vanish, we can properly say that the state is $K$th-order unpolarized, as it lacks of polarization information to that order. First-order unpolarized states coincide with the corresponding classical ones, whereas unpolarized to any order tally with the quantum notion of fully invariant states. In between these two extreme cases, there is a rich variety of situations that are explored here. The existence of \textit{hidden} polarisation emerges in a natural way in this context.Comment: 7 pages, 3 eps-color figures. Submitted to PRA. Comments welcome

Multiexcitons confined within a sub-excitonic volume: Spectroscopic and dynamical signatures of neutral and charged biexcitons in ultrasmall semiconductor nanocrystals

The use of ultrafast gating techniques allows us to resolve both spectrally and temporally the emission from short-lived neutral and negatively charged biexcitons in ultrasmall (sub-10 nm) CdSe nanocrystals (nanocrystal quantum dots). Because of forced overlap of electronic wave functions and reduced dielectric screening, these states are characterized by giant interaction energies of tens (neutral biexcitons) to hundreds (charged biexcitons) of meV. Both types of biexcitons show extremely short lifetimes (from sub-100 picoseconds to sub-picosecond time scales) that rapidly shorten with decreasing nanocrystal size. These ultrafast relaxation dynamics are explained in terms of highly efficient nonradiative Auger recombination.Comment: 5 pages, 4 figures, to be published in Phys. Rev.

Real-time Chern-Simons term for hypermagnetic fields

If non-vanishing chemical potentials are assigned to chiral fermions, then a Chern-Simons term is induced for the corresponding gauge fields. In thermal equilibrium anomalous processes adjust the chemical potentials such that the coefficient of the Chern-Simons term vanishes, but it has been argued that there are non-equilibrium epochs in cosmology where this is not the case and that, consequently, certain fermionic number densities and large-scale (hypermagnetic) field strengths get coupled to each other. We generalise the Chern-Simons term to a real-time situation relevant for dynamical considerations, by deriving the anomalous Hard Thermal Loop effective action for the hypermagnetic fields, write down the corresponding equations of motion, and discuss some exponentially growing solutions thereof.Comment: 13 page

Taste as making of the design profession

The article describes the potentiality of phenomenon "taste" in vocational training the designerВ статье делается попытка раскрыть феномен «вкуса» в профессиональной подготовке дизайнер

Interpretations in education at global processes as the conflict

Authors state model development of nonclassical pedagogics in conditions of global processesВ статье сделана попытка смоделировать развитие неклассической педагогики в условиях глобализаци

Aesthetics ignorance in the paradigm of design

Authors open the reasons professional ignorance in designВ статье сделана попытка раскрыть причины профессионального невежества в дизайн

Infographics as didactic design

This paper about the phenomenon of info graphics like necessary component of didactic infodesignВ статье представлен феномен инфографики как инструментальные технологии и средства дидактического инфодизайн

Problems of quality of design-formation in professional-pedagogical system

The article describes of the analysis of quality of preparation of the designer-teacherВ статье делается попытка анализа качества подготовки дизайнера-педагог

Pedagogical artistry in professional pedagogical paradigm

The article describes of pedagogical virtuosity as necessary component of professional skillВ статье раскрываются основы педагогического артистизма как необходимого компонента профессионального мастерств

Quantum polarization tomography of bright squeezed light

We reconstruct the polarization sector of a bright polarization squeezed beam starting from a complete set of Stokes measurements. Given the symmetry that underlies the polarization structure of quantum fields, we use the unique SU(2) Wigner distribution to represent states. In the limit of localized and bright states, the Wigner function can be approximated by an inverse three-dimensional Radon transform. We compare this direct reconstruction with the results of a maximum likelihood estimation, finding an excellent agreement.Comment: 15 pages, 5 figures. Contribution to New Journal of Physics, Focus Issue on Quantum Tomography. Comments welcom