arXiv subjects

Helene Perrin

Publications and source records attributed to Helene Perrin.

6 recordsLinked to original sources

arXiv2019

Oscillations and decay of superfluid currents in a one-dimensional Bose gas on a ring

We study the time evolution of a supercurrent imprinted on a one-dimensional ring of interacting bosons in the presence of a defect created by a localized barrier. Depending on interaction strength and temperature, we identify various dynamical regimes where the current oscillates, is self-trapped or decays with time. We show that the dynamics are captured by a dual Josephson model and involve phase slips of thermal or quantum nature.

cond-mat.quant-gas↗

arXiv2017

MEDOC: a Python wrapper to load MEDLINE into a local MySQL database

Since the MEDLINE database was released, the number of documents indexed by this entity has risen every year. Several tools have been developed by the National Institutes of Health (NIH) to query this corpus of scientific publications. However, in terms of advances in big data, text-mining and data science, an option to build a local relational database containing all metadata available on MEDLINE would be truly useful to optimally exploit these resources. MEDOC (MEdline DOwnloading Contrivance) is a Python program designed to download data on an FTP and to load all extracted information into a local MySQL database. It took MEDOC 4 days and 17 hours to load the 26 million documents available on this server onto a standard computer. This indexed relational database allows the user to build complex and rapid queries. All fields can thus be searched for desired information, a task that is difficult to accomplish through the PubMed graphical interface. MEDOC is free and publicly available at https://github.com/MrMimic/MEDOC.

cs.DL↗

arXiv2017

OMICtools: a community-driven search engine for biological data analysis

With high-throughput biotechnologies generating unprecedented quantities of data, researchers are faced with the challenge of locating and comparing an exponentially growing number of programs and websites dedicated to computational biology, in order to maximize the potential of their data. OMICtools is designed to meet this need with its open-access search engine offering an easy means of locating the right tools corresponding to each researcher and their specific biological data analyses. The OMICtools website (https://OMICtools.com) centralizes more than 18,500 software tools and databases, manually classified, by a team of biocurators including many scientific experts. Key information, a direct link, and access to discussions and evaluations by the biomedical community are provided for each tool. Anyone can join the OMICtools community and create a profile page, to share their expertise and comment on tools. In addition, developers can directly upload their code versions which are registered for identification and citation in scientific publications, improving research traceability. The OMICtools community links thousands of life scientists and developers worldwide, who use this bioinformatics platform to accelerate their projects and biological data analyses.

cs.IR↗

arXiv2006

Diffuse reflection of a Bose-Einstein condensate from a rough evanescent wave mirror

We present experimental results showing the diffuse reflection of a Bose-Einstein condensate from a rough mirror, consisting of a dielectric substrate supporting a blue-detuned evanescent wave. The scattering is anisotropic, more pronounced in the direction of the surface propagation of the evanescent wave. These results agree very well with theoretical predictions.

physics.atom-ph↗

arXiv2004

Ultracold atoms confined in rf-induced two-dimensional trapping potentials

We present the experimental implementation of a new trap for cold atoms proposed by O. Zobay and B. M. Garraway. It relies on adiabatic potentials for atoms dressed by a rf field in an inhomogeneous magnetic field. This trap is well suited to confine atoms tightly along one direction to produce a two-dimensional atomic gas. We transferred ultracold atoms into this trap, starting either from thermal samples or Bose--Einstein condensates. In the latter case, technical noise during the loading stage caused heating and prevented us from observing 2D BECs.

quant-ph↗

arXiv2003

Schemes for loading a Bose-Einstein condensate into a two-dimensional dipole trap

We propose two loading mechanisms of a degenerate Bose gas into a surface trap. This trap relies on the dipole potential produced by two evanescent optical waves far detuned from the atomic resonance, yielding a strongly anisotropic trap with typical frequencies 40 Hz x 65 Hz x 30 kHz. We present numerical simulations based on the time-dependent Gross-Pitaevskii equation of the transfer process from a conventional magnetic trap into the surface trap. We show that, despite a large discrepancy between the oscillation frequencies along one direction in the initial and final traps, a loading time of a few tens of milliseconds would lead to an adiabatic transfer. Preliminary experimental results are presented.

cond-mat↗