Strong Einstein-Podolsky-Rosen entanglement from a single squeezed light source

Einstein-Podolsky-Rosen (EPR) entanglement is a criterion that is more demanding than just certifying entanglement. We theoretically and experimentally analyze the low resource generation of bi-partite continuous variable entanglement, as realized by mixing a squeezed mode with a vacuum mode at a balanced beam splitter, i.e. the generation of so-called vacuum-class entanglement. We find that in order to observe EPR entanglement the total optical loss must be smaller than 33.3 %. However, arbitrary strong EPR entanglement is generally possible with this scheme. We realize continuous wave squeezed light at 1550 nm with up to 9.9 dB of non-classical noise reduction, which is the highest value at a telecom wavelength so far. Using two phase controlled balanced homodyne detectors we observe an EPR co-variance product of 0.502 \pm 0.006 < 1, where 1 is the critical value. We discuss the feasibility of strong Gaussian entanglement and its application for quantum key distribution in a short-distance fiber network.Comment: 4 pages, 4 figure

Thermal Decomposition and Combustion of γ-irradiated Polyamide 6 Containing Phosphorus Oxynitride or Phospham

Polyamide 6 (PA-6) containing the fire retardants phosphorus oxynitride ((PON)m) or phospham ((PN2H)n) was exposed to 60Co-γ-rays (absorbed dose: 1.0–4.0 MGy). The irradiation led to crosslinking of the polymer which caused an increase in the char yield and a decrease in the flammability of the polymer. The combustion behavior was strongly affected by irradiation: dripping was totally prevented in the case of system PA-6/(PN2H)n and strongly retarded in the case of system PA-6/(PON)m. The thermal stability of the system PA-6/(PN2H)n decreased with increasing absorbed dose whereas the thermal stability of the system PA-6/(PON)m did not change

Trench width dependant deeply etched surface-defined InP gratings for low-cost high speed DFB/DBR

In this paper we are reporting a fabrication process for multi-section telecom lasers based on surface defined lateral gratings, which is compatible with low-cost high-throughput nano-imprint lithography. A new grating definition process is developed, which allow a better control of the cross section geometry to obtain higher coupling strength

Loneliness and Deprivation: The Case of Roman Catholic Priests

Using Roman Catholic Priests as a test in order to control for deprivation in relationships of intimacy while maximizing the need for social network relationships, an examination was made of their differential experience of loneliness. The evidence suggested repeatedly that priests were more likely to experience loneliness as a serious problem when they perceived that the social network which they regarded as most significant in their lives (the Church) placed some kind of structural limitation on the extent of their involvement in it. Factors, for example, which help determine the individual priest\u27s place in the structure of the Church are: type of assignment, length of time ordained, and degree of integration into the network through mutual commitment; all of these factors correlate significantly with the experience of loneliness. For priests experiencing serious loneliness, there were further significant correlations with a perceived deficit in intimacy, an expressed need for sexual intimacy, a desire to marry, and more frequent dating behavior. While causal sequences could not be established with certainty, the use of Guttman scaling techniques and a logical ordering of the variables suggests strongly that an emotional response (in this case an exaggerated search for intimate relationships) may have been triggered by social deprivation (network exclusion) rather than by an emotional deprivation (in intimacy) as might have been expected. Such a possibility has far-reaching implications and calls for further research. If an exaggerated search for intimate relationships can be triggered by social network deprivation, that might shed light on a variety of other phenomena such as promiscuity and rape, especially in urban, industrialized societies whose character is such that secondary relationehips become more pervasive and achieve such great importance in the minds and daily lives of the people

Implementation of Quantum Key Distribution with Composable Security Against Coherent Attacks using Einstein-Podolsky-Rosen Entanglement

Secret communication over public channels is one of the central pillars of a modern information society. Using quantum key distribution (QKD) this is achieved without relying on the hardness of mathematical problems which might be compromised by improved algorithms or by future quantum computers. State-of-the-art QKD requires composable security against coherent attacks for a finite number of samples. Here, we present the first implementation of QKD satisfying this requirement and additionally achieving security which is independent of any possible flaws in the implementation of the receiver. By distributing strongly Einstein-Podolsky-Rosen entangled continuous variable (CV) light in a table-top arrangement, we generated secret keys using a highly efficient error reconciliation algorithm. Since CV encoding is compatible with conventional optical communication technology, we consider our work to be a major promotion for commercialized QKD providing composable security against the most general channel attacks.Comment: 7 pages, 3 figure