Un troisième ombilic du rêve gestateur de l’émergence de mythes ?

Ce travail s’appuie sur les propositions respectives de Bion et de Kaës soulignant les relations étroites dans la psyché du mythe et du rêve. Bion conçoit que les mythes et les rêves s’originent d’un même temps inaugural de croissance de la pensée dans l’évolution psychique. Quant à René Kaës, il a récemment théorisé l’idée d’espaces oniriques interpsychiques communs et partagés et l’existence de trois ombilics du rêve. Mon investigation de l’usage intensif des rêves dans le mythe de l’épopée de Gilgamesh soulignera la pertinence de ces perspectives. Il s’y révèle en effet l’intrication de la construction du mythe avec les rêves au sein de l’évolution psychique, ainsi que l’importance du caractère relationnel du rêve qui, articulé aux représentations culturelles et sociales va fonder le mycélium d’un troisième ombilic, obscur noyau de l’émergence du récit mythique. Un exemple clinique évoquera combien malgré l’impossibilité d’un patient d’accéder à ses racines culturelles spécifiques, de possibles aspects de ce troisième ombilic se manifestent pour lui de manière énigmatique, dans son activité onirique

Toward On-Demand Generation of Entangled Photon Pairs with a Quantum Dot

The generation of on-demand, optimally entangled photon pairs remains one of the most formidable challenges in the quantum optics and quantum information community. Despite the fact that recent developments in this area have opened new doors leading toward the realization of sources exhibiting either high brightness or near-unity entanglement fidelity, the challenges to achieve both together persist. Here, we will provide a historical review on the development of quantum dots (QDs) for entangled photon generation, with a focus on nanowire QDs, and address the latest research performed on nanowire QDs, including measuring entanglement fidelity, light-extraction efficiency, dephasing mechanisms, and the detrimental effects of detection systems on the measured values of entanglement fidelity. Additionally, we will discuss results recently observed pertaining to resonant excitation of a nanowire QD, revealing the potential of such sources to outperform spontaneous parametric down-conversion (SPDC) sources, providing a viable solution to the current challenges in quantum optics and quantum information

Oscillating photonic Bell state from a semiconductor quantum dot for quantum key distribution

An on-demand source of bright entangled photon pairs is desirable for quantum key distribution (QKD) and quantum repeaters. The leading candidate to generate entangled photon pairs is based on spontaneous parametric down-conversion (SPDC) in a non-linear crystal. However, there exists a fundamental trade-off between entanglement fidelity and efficiency in SPDC sources due to multiphoton emission at high brightness, which limits the pair extraction efficiency to 0.1% when operating at near-unity fidelity. Quantum dots in photonic nanostructures can in principle overcome this trade-off; however, the quantum dots that have achieved entanglement fidelities on par with SPDC sources (99%) have poor pair extraction efficiencies of 0.01%. Here, we demonstrate a 65-fold increase in the pair extraction efficiency compared to quantum dots with equivalent peak fidelity from an InAsP quantum dot in a photonic nanowire waveguide. We measure a raw peak concurrence and fidelity of 95.3% $\pm$ 0.5% and 97.5% $\pm$ 0.8%, respectively. Finally, we show that an oscillating two-photon Bell state generated by a semiconductor quantum dot can be utilized to establish a secure key for QKD, alleviating the need to remove the quantum dot energy splitting of the intermediate exciton states in the biexciton-exciton cascade.Comment: 24 pages (7 main body, excluding references plus 14 supplemental information) and 4 main body figure

Similarities and Differences between Colicin and Filamentous Phage Uptake by Bacterial Cells

International audienceGram-negative bacteria have evolved a complex envelope to adapt and survive in a broad range of ecological niches. This physical barrier is the first line of defense against noxious compounds and viral particles called bacteriophages. Colicins are a family of bactericidal proteins produced by and toxic to Escherichia coli and closely related bacteria. Filamentous phages have a complex structure, composed of at least five capsid proteins assembled in a long thread-shaped particle, that protects the viral DNA. Despite their difference in size and complexity, group A colicins and filamentous phages both parasitize multiprotein complexes of their sensitive host for entry. They first bind to a receptor located at the surface of the target bacteria before specifically recruiting components of the Tol system to cross the outer membrane and find their way through the periplasm. The Tol system is thought to use the proton motive force of the inner membrane to maintain outer membrane integrity during the life cycle of the cell. This review describes the sequential docking mechanisms of group A colicins and filamentous phages during their uptake by their bacterial host, with a specific focus on the translocation step, promoted by interactions with the Tol system