Polariton parametric photoluminescence in spatially inhomogeneous systems

A general theory of polariton parametric photoluminescence in spatially inhomogeneous systems is developed. The quantum Langevin equations are solved in a generalized Bogoliubov de Gennes approximation. We apply the formalism to the specific case of a disordered microcavity. In this case, we numerically solve the equations for the coherent emission and the photoluminescence. We describe the effect of the exciton and photon disorder on the photoluminescence pattern exhibited in momentum space, finding a good agreement with the experimental observations

Dipole states in stable and unstable nuclei

A nuclear structure model based on linear response theory (i.e., Random Phase Approximation) and which includes pairing correlations and anharmonicities (coupling with collective vibrations), has been implemented in such a way that it can be applied on the same footing to magic as well as open-shell nuclei. As applications, we have chosen to study the dipole excitations both in well-known, stable isotopes like $^{208}$Pb and $^{120}$Sn as well as in the neutron-rich, unstable $^{132}$Sn nucleus, by addressing in the latter case the question about the nature of the low-lying strength. Our results suggest that the model is reliable and predicts in all cases low-lying strength of non collective nature.Comment: 16 pages, 6 figures; submitted for publicatio

Spectrum and thermal fluctuations of a microcavity polariton Bose-Einstein condensate

The Hartree-Fock-Popov theory of interacting Bose particles is developed, for modeling exciton-polaritons in semiconductor microcavities undergoing Bose-Einstein condensation. A self-consistent treatment of the linear exciton-photon coupling and of the exciton non-linearity provides a thermal equilibrium description of the collective excitation spectrum, of the polariton energy shifts and of the phase diagram. Quantitative predictions support recent experimental findings

Neuroeducación con enfoque militar y acciones contra el acoso y abuso sexual en centros educativos

La educación como proceso social que contribuye al bienestar de la comunidad tiene en su haber velar por la integridad y buen funcionamiento en los planteles educativos. La educación es un elemento variable en las sociedades pues se ve expuesta desde épocas remotas a constante cambio y transformación; por lo que el docente y facilitador requiere de amplia capacidad de adaptación, entonces se produce el surgimiento de diversas: teorías, estrategias, metodologías y prácticas que dependen de los resultados que se presentan en las y los estudiantes que forman parte del sistema educativo dentro de su proceso de aprendizaje. La Neurodidáctica o Neuroeducación se enfrenta a un obstáculo que consiste en cómo lograr que el cerebro del estudiante se encuentre en condiciones de aprender y al mismo tiempo pueda poner en práctica lo aprendido, de tal manera que se vea beneficiado a sí mismo y al entorno que lo rodea, por lo tanto, este fue el punto de partida de diversas investigaciones que llegaron a conclusiones interesantes

Partially suppressed long-range order in the Bose-Einstein condensation of polaritons

We adopt a kinetic theory of polariton non-equilibrium Bose-Einstein condensation, to describe the formation of off-diagonal long-range order. The theory accounts properly for the dominant role of quantum fluctuations in the condensate. In realistic situations with optical excitation at high energy, it predicts a significant depletion of the condensate caused by long-wavelength fluctuations. As a consequence, the one-body density matrix in space displays a partially suppressed long-range order and a pronounced dependence on the finite size of the system