Photon Sorting, Efficient Bell Measurements and a Deterministic CZ Gate using a Passive Two-level Nonlinearity

Although the strengths of optical non-linearities available experimentally have been rapidly increasing in recent years, significant challenges remain to using such non-linearities to produce useful quantum devices such as efficient optical Bell state analysers or universal quantum optical gates. Here we describe a new approach that avoids the current limitations by combining strong non-linearities with active Gaussian operations in efficient protocols for Bell state analysers and Controlled-Sign gates

Squeezed Light Generation in Nonlinear System with Chaotic Dynamics

The squeezing in a nonlinear system with chaotic dynamics is considered. The model describing interaction of collection of two-level atoms with a single-mode of self-consistent field and an external field is analyzed. It is shown that in the semiclassical limit, in contrast to the regular behaviour, the chaotic dynamics result in: (i) an increase in squeezing, (ii) unstable squeezing and contraction of time intervals of squeezing on large enough times. The possibility of the experimental observation of the described effects is discussed.Comment: 12 pages, RevTEX (EPSF-style), 6 figure

Choosing a Better Delay Line Medium between Single-Mode and Multi-Mode Optical Fibers: the Effect of Bending

Optical fiber cables are materials whose core is made of silica and other materials such as chalcogenide glasses; they transmit a digital signal via light pulses through an extremely thin strand of glass. The light propagates and is being guided by the core which is surrounded by the cladding. Light travels in the optical fiber in the form of total internal reflection in the core of the fibers. The flexibility, low tensile strength, low signal loss, high bandwidth and other characteristics of optical fibers favors it for use as a delay medium in many applications. Another favorable characteristic of optical fiber delay lines is are their relative insensitivities to environmental effects and electromagnetic interferences. The immunity of optical fibers to interferences and their less weight added advantages to it for use as delay medium. Single-mode and multi-mode are the two most popular types of optical fibers. Single-mode fibers have good propagation and delay properties with a minimal loss that allows the signal to propagate in a large distance with insignificant distortion or attenuation. The percentage of power transmission of single-mode fibers is found to be higher than that of the multi-mode fibers. It is, therefore, a preferred type for use as a delay line. In this paper, relative studies of the two optical fibers modes, and the results of power input/output measurement of the two modes are presented with a view to coming up with a better type for use as a delay medium

Sociodemographic, psychological and politicocultural correlates in Flemish students' attitudes towards French and English

An analysis of 100 Flemish high-school students' attitudes towards French and English (both foreign languages) revealed complex links etween personality factors, gender, politicocultural identity, communicative behaviour and foreign language attitudes. Attitudes towards English were found to be much more positive than those towards French, despite the fact that the participants had enjoyed a longer and more intense formal instruction in French (it being their second language). The independent variables were found to have stronger effects for French than for English, with the exception of politicocultural identity of the participant, which had a strong effect on attitudes towards French but not English. Overall, it seems that social factors, including exposure to the foreign languages, are linked with lowerlevel personality dimensions and thus shape attitudes towards these languages