Experimental generation of complex noisy photonic entanglement

We present an experimental scheme based on spontaneous parametric down-conversion to produce multiple photon pairs in maximally entangled polarization states using an arrangement of two type-I nonlinear crystals. By introducing correlated polarization noise in the paths of the generated photons we prepare mixed entangled states whose properties illustrate fundamental results obtained recently in quantum information theory, in particular those concerning bound entanglement and privacy.Comment: 12 pages, 3 figure

Experimental Extraction of Secure Correlations from a Noisy Private State

We report experimental generation of a noisy entangled four-photon state that exhibits a separation between the secure key contents and distillable entanglement, a hallmark feature of the recently established quantum theory of private states. The privacy analysis, based on the full tomographic reconstruction of the prepared state, is utilized in a proof-of-principle key generation. The inferiority of distillation-based strategies to extract the key is exposed by an implementation of an entanglement distillation protocol for the produced state.Comment: 5 pages, 3 figures, final versio

Towards illiberal conditioning? New politics of media regulations in Poland (2015–2018)

In this article, we examine how media policy changes aid de-democratisation in Poland. Unfolding the logic underpinning the new politics of media regulations, this article argues that media policy paints a nuanced picture of democratic backsliding. Our Foucault-inspired discourse analysis of media policy archive focuses on the rise of illiberal trends at the cross-roads of the Polish hybrid media system, democracy and society. We find these trends display the features of centralisation of power, cultural politics, political partisanship and social polarisations. We explain these notions, using the concepts of “executive aggrandisement” and “politicisation” of public service media sector

The Influence of Temperature on Coumarin 153 Fluorescence Kinetics

The influence of temperature varied in the range 183 K–323 K on the fluorescence quantum yield, fluorescence lifetime, absorption and emission transition moments and non-radiative deactivation rate was determined for the well known and largely used dye Coumarin 153, dissolved in 1-chloropropane. The Kennard-Stepanov relation connecting the absorption and emission spectra was used to check for the presence of more than one absorbing/emitting species and to investigate whether intramolecular vibrational redistribution completes in the C153 excited S1 state before the emission takes place. The emission spectrum corresponding to S1→S0 transition, was fitted at each temperature to the model function including the information on the dye vibrational modes coupling. In this way the displacement in equilibrium distance for the most active vibrational mode was determined for C153 in S1 and in S0. Using the temperature dependence of the fluorescence decay time and quantum yield, the non-radiative deactivation rate was determined. Its temperature dependence was compared to that calculated using the theoretical model with the most active vibrational mode displacement values taken from steady-state spectra analysis. The somewhat surprising dependence of the fluorescence decay time and quantum yield on temperature was related to non-trivial coupling between low-frequency vibrational modes of C153 in the excited and ground states

Bivariate adjustments for interplot competition in variety trials

International audienc

Experimental security analysis a four-photon private state

We report experimental generation of a noisy entangled four-photon state that exhibits a separation between secure key contents and distillable entanglement. This difference is exposed by a detailed analysis of its privacy properties. © 2010 Optical Society of America

Experimental security analysis a four-photon private state

We report experimental generation of a noisy entangled four-photon state that exhibits a separation between secure key contents and distillable entanglement. This difference is exposed by a detailed analysis of its privacy properties. © 2010 Optical Society of America