Events

26e Journée du GAP Jeudi 31 Mai 2018 Université de Genève L’Ecole de Physique Le Grand Auditoire 24, Quai Ernest-Ansermet Genève

Dr Matteo Montagnese Physikalishes Institut der Universität zu Köln Seminar room 2pm Friday 19th May 2017

25ème Journée du GAP Mercredi 17 mai 2017 Université de Genève Battelle – Bâtiment C Salle C301 Route de Drize 7 1227 Carouge

Stefan Wolf de l’Université de Lugano, Pinchat, Seminar room, 4:15pm Landauer's principle claims that "Information is Physical." A flavor of its conceptual antipode, Wheeler's "It from Bit," is the Church/Turing thesis: All natural processes can be computed by a universal Turing machine. Physical laws then become descriptions of subsets of actually observable, as opposed to merely possible, computations. Bell correlations imply a separation: Either beyond-Turing computations are impossible in nature, or they can be carried out even by single photons.

Fernando Monteiro Thesis Defence Pinchat, Seminar Room, 11:15am

Prof. Alex Lvovsky, University of Calgary, Canada, and the Russian Quantum Center, Moscow-Russia Lundi 3 octobre à 10:00, Salle de séminaire de Pinchat

We are pleased to inform you that the bar du GAP 2016 will take place on Friday September 23 starting at 8:00PM! The theme of the party is Hollywood/cinema. Free entrance / we sell cheap drinks / one free drink if you are disguised.

Morgan Weston, Griffith University, Australia. Entanglement is a key resource to many quantum information protocols, making rigorous verification of remote shared entanglement highly sought after. We design and experimentally implement a new heralded quantum steering protocol in order to verify shared entanglement over a high loss quantum channel, with the detection loophole closed. Our scheme uses entanglement swapping with two high-performance telecom-wavelength, polarisation-entangled photon sources and highly efficient detectors. Our approach has demonstrated violation of the steering inequality by two standard deviations with 14.8 dB of added channel loss, equivalent to approximately 80km of telecom fibre.

Joseph Ho, Griffith University, Australia. While the salient features of a quantum computer have been shown in proof-of-principle experiments, e.g., single- and two-qubit gates forming a universal gate set, difficulties in scaling up the quantum systems to control multiple qubits have made demonstrations of mode complex operations intractable. This is exemplified by the classical Fredkin (or controlled-SWAP) gate for which, despite many theoretical proposals, a true quantum analogue has yet to be realised. Here, by directly adding control to the two qubit SWAP unitary, we use photonic qubit logic to report on one of the first experimental demonstration of a quantum Fredkin gate.

Random number generators are essential to ensure performance in information technologies, including cryptography, stochastic simulations and massive data processing. The quality of random numbers ultimately determines the security and privacy that can be achieved, while the speed at which they can be generated poses limits to the utilisation of the available resources. In this work we propose and demonstrate a quantum entropy source for random number generation on an indium phosphide photonic integrated circuit made possible by a new design using two-laser interference and heterodyne detection. The resulting device offers high-speed operation with unprecedented security guarantees and reduced form factor. It is also compatible with complementary metal-oxide semiconductor technology, opening the path to its integration in computation and communication electronic cards, which is particularly relevant for the intensive migration of information processing and storage tasks from local premises to cloud data centres.