Inauguration de l'INTRIQ (Institut transdisciplinaire d'informatique quantique)
Jeudi 9 novembre 2006
6214 et au Salon Maurice L'Abbé du Pavillon André-Aisenstadt de l'Université de Montréal (2920 Chemin de la Tour).

09:30 croissants, café
10:29 Mots de bienvenue, Gilles Brassard & François Lalonde
10:30 Barry Sanders, University of Calgary, Implementing quantum information
11:15 Michele Mosca, University of Waterloo Self-testing of quantum circuits

12:00 Lunch

14:00 Chip Elliott, BBN, Architectures for quantum networks
14:45 John Watrous, University of Waterloo, Zero-knowledge against quantum attacks
15:45 coffee break
16:15 Charles H. Bennett, IBM Research, Privacy, Publicity, and Permanence of Information
17:15 Première réunion plénière des membres de l'INTRIQ (membres seulement)
18:15 Réception


Charles H. Bennett
Privacy, Publicity, and Permanence of Information

The most private information, exemplified by a quantum eraser experiment, exists only conditionally and temporarily--after the experiment is over even God no longer remembers what "happened". Less private are classical secrets, known only to a few, or information--like the lost poems of Sappho--that once was public but has been lost over time. Finally there is information that has been replicated and propagated so widely as to be infeasible to conceal and unlikely to be forgotten. Modern information technology has caused an explosion of such information, with the beneficial side effect of making it harder for tyrants to rewrite the history of their misdeeds; and it is tempting to hope that all macroscopic information is permanent, making such cover-ups impossible in principle. However, by comparing entropy flows into and out of the Earth with estimates of the planet's storage capacity, we conclude that most macroscopic information--for example the pattern of sand grains on an ancient beach--is impermanent, in the sense of becoming irrecoverable in principle from the Earth, though still recorded in the Universe.

Chip Elliott
Architectures for Quantum Networks

The beautiful vision of quantum communications is now almost within reach. Entanglement, teleportation, and quantum relays have all been demonstrated - but how can true quantum networking become an engineering reality? Can we really build a global quantum Internet? We review recent developments in the DARPA Quantum Network, and look forward to new architectures for quantum networks that just might be possible within a few years.

Michele Mosca
Self-Testing of Quantum Circuits

Abstract: I will explain how a quantum circuit together with measurement apparatuses and EPR sources can be fully verified without any reference to some other trusted set of quantum devices. Our main assumption is that the physical system we are working with consists of several identifiable sub-systems, on which we can apply some given gates locally. To achieve our goal we define the notions of simulation and equivalence. The concept of simulation refers to producing the correct probabilities when measuring physical systems. The notion of equivalence is used to enable the efficient testing of the composition of quantum operations. Unlike simulation, which refers to measured quantities (i.e., probabilities of outcomes), equivalence relates mathematical objects like states, subspaces or gates. Using these two concepts, we prove that if a system satisfies some simulation conditions, then it is equivalent to the one it is supposed to implement. In addition, with our formalism, we can show that these statements are robust, and the degree of robustness can be made explicit. Finally, we design a test for any quantum circuit whose complexity is linear in the number of gates and qubits, and polynomial in the required precision. Joint work with Frederic Magniez, Dominic Mayers and Harold Ollivier

Barry Sanders
Implementing Quantum Information

Although quantum information is challenging to implement, we are fortunate to have several promising technologies, such as coding, transmitting, processing, and reading quantum information in light, atomic nuclei, cold atoms, superconductors, and solid state. We will survey these technologies, weigh up their advantages, and consider hybridizing quantum information to convert quantum information between different media so that we can exploit the advantages and minimize the obstacles.

John Watrous
Zero-Knowledge Against Quantum Attacks

It was an unsolved problem in theoretical quantum cryptography for several years to formulate a general and cryptographically meaningful definition of quantum zero-knowledge and to apply the definition to non-trivial protocols. In this talk I will explain how this problem can be solved, at least to a significant extent, for what are arguably the strongest and most natural definitions of quantum zero-knowledge.