2,076 research outputs found
Trellises for stabilizer codes: definition and uses
Trellises play an important theoretical and practical role for classical
codes. Their main utility is to devise complexity-efficient error estimation
algorithms. Here, we describe trellis representations for quantum stabilizer
codes. We show that they share the same properties as their classical analogs.
In particular, for any stabilizer code it is possible to find a minimal trellis
representation. Our construction is illustrated by two fundamental error
estimation algorithms.Comment: 5 pages, 2 figure
Transdet: a matched-filter based algorithm for transit detection - application to simulated COROT light curves
We present a matched-filter based algorithm for transit detection and its
application to simulated COROT light curves. This algorithm stems from the work
by Bord\'e, Rouan & L\'eger (2003). We describe the different steps we intend
to take to discriminate between planets and stellar companions using the three
photometric bands provided by COROT. These steps include the search for
secondary transits, the search for ellipsoidal variability, and the study of
transit chromaticity. We also discuss the performance of this approach in the
context of blind tests organized inside the COROT exoplanet consortium.Comment: 6 pages, 4 figures, in Transiting Extrasolar Planets Workshop,
meeting held in Heidelberg, 25-28 September 200
Managing Operating Procedures in Distributed Collaborative Projects
In recent years, large distributed collaborative projects have become very prominent in scientific research, allowing exchanges between laboratories located in different institutions and countries and between various domains of competence. Particularly the work on nanotoxicity – a field which has only been under investigation for a few years and is still lacking regulatory framework – highlighted the need for well-controlled methods, as well as rules for the handling and disposal of used materials. To obtain comparable and reproducible results of experiments conducted in a distributed context, the standardisation and proper documentation of the applied methods is crucial. The European project NanoDiaRA, whose aim is to develop nanoparticles and biomarkers for the early diagnosis of inflammatory disease, faces this situation as it involves 15 European partners and brings together different scientific cultures and professional backgrounds. Protocols especially developed for Superparamagnetic Iron Oxide Nanoparticles and a management system were designed and implemented within the NanoDiaRA project to fulfil those needs. The main goals were the establishment of standardised Standard Operating Procedures assuring transparency and reproducibility and the provision of access to these protocols to every project partner, as well as their clear allocation to carry out precise measurements and production steps
Absence of strong magnetic fluctuations in the iron phosphide superconductors LaFePO and Sr2ScO3FeP
We report neutron inelastic scattering measurements on polycrystalline LaFePO
and Sr2ScO3FeP, two members of the iron phosphide families of superconductors.
No evidence is found for any magnetic fluctuations in the spectrum of either
material in the energy and wavevector ranges probed. Special attention is paid
to the wavevector at which spin-density-wave-like fluctuations are seen in
other iron-based superconductors. We estimate that the magnetic signal, if
present, is at least a factor of four (Sr2ScO3FeP) or seven (LaFePO) smaller
than in the related iron arsenide and chalcogenide superconductors. These
results suggest that magnetic fluctuations are not as influential on the
electronic properties of the iron phosphide systems as they are in other
iron-based superconductors.Comment: 7 pages, 5 figure
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