Gonçalo Quinta and Rui André, from Instituto Superior Técnico
Date & time: Wednesday, December 5th, 16:00h
Location: Instituto Superior Técnico, Lisbon, Seminar room (2.8.3), Physics Building
We present a classification scheme for quantum entanglement based on topological links. This is done by identifying a nonrigid ring to a particle, attributing the act of cutting and removing a ring to the operation of tracing out the particle, and associating linked rings to entangled particles. This analogy naturally leads us to a classification of multipartite quantum entanglement based on all possible distinct links for any given number of rings. We demonstrate the use of this new classification scheme for three and four qubits and its potential in the context of qubit networks. More Information..
IT will be organizing the seminar “Millimeter-wave antennas for 5G networks”, with talks by Prof. Eduardo Motta Cruz, from the Ecole Polytechnique of Nantes, France, and Professor Manuel Arrebola, from the University of Oviedo, Spain.
Date & time: Friday, November 30th, 10:30h
Location: meeting room of IT, 11th floor, North Tower, Técnico Lisboa
Title: “Developments of antenna systems future telecommunications networks”, by Eduardo Motta Cruz (Biography in: https://www.ietr.fr/?auteur1032&lang=en)
This workshop, proposed by Mr. Eduardo MOTTA CRUZ, is dedicated to the research activities of the IETR laboratory (CNRS - France), led by the department “Antennas and Microwave Devices”, especially the BEAMS team (BEAM Antennas up to Mm and Submm waves).
The main activities concern the design of new sectorial, multi-beam, beam-deflection or high directivity millimetric antennas for different communication networks, using several technologies and characterization techniques, with a focus on future 5G networks.
Title: “Efficient Techniques for the Modelling and Optimization of Reflectarray Antennas”, by Manuel Arrebola (Biography in: http://www.uniovi.es/en/-/arrebola-baena-manuel)
Printed reflectarray antennas have been considered as a smart solution for different applications since they exhibit some interesting properties and avoid inconveniences of reflector or phased-array antennas. However, they show limitations, mainly in the bandwidth and crosspolar level. An optimization process is required in order to improve these parameters and others but the technique are time and memory demanding because of the size of the problem being most of times unaffordable. Thus, a number of improvements in the basic technique are proposed, including the use of differential contributions or efficient cell modelling through Machine Learning (SVMs). The talk is divided into two parts. In the first one, the principle of work of shaped-beam reflectarray is presented, as well as the framework of the proposed technique and the challenges to be achieved. In the second part, some results of optimization of reflectarray antennas will be shown, including beam shaping, crosspolar reduction and direct optimization, discussing the efficiency and accuracy of the techniques.