Creating and sharing knowledge for telecommunications

Symposium on Complex Networks: from Classical to Quantum

on 16-10-2017

... Date: Monday 16 October 2017
Time: 17:00
Venue: Abreu Faro Amphitheatre, Interdisciplinary Building, IST, Lisbon

17:00 - Albert-László Barabási (Center of Complex Networks Research, Northeastern University & Division of Network Medicine, Harvard University): Taming Complexity: Controlling Networks

17:45 - Yasser Omar (Instituto Superior Técnico & Instituto de Telecomunicações): The Emergence of Complex Quantum Networks

18:30 - end.

Taming Complexity: Controlling Networks

Albert-László Barabási (Center of Complex Networks Research, Northeastern University & Division of Network Medicine, Harvard University)

Abstract: The ultimate proof of our understanding of biological or technological systems is reflected in our ability to control them. While control theory offers mathematical tools to steer engineered and natural systems towards a desired state, we lack a framework to control complex self-organized systems. Here I will explore the controllability of an arbitrary complex network, identifying the set of driver nodes whose time-dependent control can guide the system's entire dynamics. Virtually all technological and biological networks must be able to control their internal processes. Given that, issues related to control deeply shape the topology and the vulnerability of real systems. Consequently, unveiling the control principles of real networks, the goal of our research, forces us to address series of fundamental questions pertaining to our understanding of complex systems. Finally, I will discuss how control principles inform our ability to predict neurons involved in specific processes in the brain, offering an avenue to experimentally falsify and test the predictions of network control.

The Emergence of Complex Quantum Networks

Yasser Omar (Instituto Superior Técnico & Instituto de Telecomunicações)

Abstract: Complex network theory and quantum physics are being brought together to define and study a new subject: complex quantum networks. But what exactly are complex quantum networks? And can they play a role in our understanding of fundamental science? And what is their role in quantum technologies, namely in quantum computation and in quantum communications? In this talk I will discuss what we know so far and what challenges lie ahead in this novel research domain.

Supported by: IST, IT, and project NQuN – The Nature of Quantum Networks, John Templeton Foundation (Grant Agreement n. 60478).

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How correspondents in orbit may realise Quantum Communications with ground and why

on 13-10-2017

... Paolo Villoresi, University of Padova

Friday 13/10/2017, 11:00
Room 3.10, Mathematics Building, IST

The paradigm shift that Quantum Communications represent vs. classical counterpart allows envisaging the global application of Quantum Information protocols as the cryptographic key distribution as well as of the use of the qubits as a probe for fundamental tests of Quantum Mechanics and Gravity on a scale beyond terrestrial limits.
Quantum Communications on planetary scale require complementary channels including ground and satellite links. As the former have progressed up to commercial stage using fiber-cables, it's crucial the study of links for space QC and eventually the demonstration of protocols such as quantum-key-distribution (QKD) and quantum teleportation along satellite-to-ground or intersatellite links.
We shall report on the extension of the Quantum Communications and Technologies to long distances, on the surface of the Earth as well as from the Earth to an orbiting terminal in Space. This is influenced by hurdles as the large losses, the effects on the optical propagation of the turbulent medium and the relative motion of terminals. Nevertheless, it was possible to demonstrate the Quantum Communications with Low-Earth-Orbit satellites using polarization degree of freedom to encode the qubits.
Temporal modes were used to demonstrate the quantum interference along a Space channel will be also described.
The recent results on the extension to Space of the Gedanken experiment proposed by John Wheeler on the wave-particle duality, then about the very nature of the quantum entities, will be described.

Quantum Computation and Information Seminar
Support: Phys-Info (IT), SQIG (IT) and CAMGSD, with support from FCT, FEDER and EU FP7, namely via the Doctoral Programme in the Physics and Mathematics of Information (DP-PMI), and projects PEst-OE/EEI/LA0008/2013, QuNet and NQuN.

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