Seminar

Marco Piani, University of Strathclyde, Glascow

Quantum correlations exhibit a variety of non-classical features, which include quantum entanglement, quantum steering, and quantum discord. Such richness and diversity of quantum features calls for meaningful and quantitative approaches to their study. In this talk I will illustrate how it is possible to exploit techniques and insight from convex optimization, especially from semidefinite programming, to provide an operational quantification and interpretation of all the above aspects of the quantumness of correlations.

Wednesday, August 5, 2015 10:00 am - 11:00 am EDT (GMT -04:00)

Britton Plourde: Superconducting metamaterials and asymmetric transmon qubits

Britton Plourde, University of Syracuse

Low-loss resonators formed from lumped circuit elements or distributed transmission lines can be coupled to superconducting qubits. This is the basis for the numerous investigations of circuit-QED over the past decade. In this case, one is primarily interested in the coupling between the qubit and one or a few modes.

Tuesday, June 30, 2015 11:00 am - 12:00 pm EDT (GMT -04:00)

Dong Yang: Operational resource theory of coherence

Dong Yang, University of Barcelona

From the viewpoint of resource theory, we establish the coherence
theory in an operational way. Namely we introduce the two basic concepts
— “coherence distillation” and “coherence cost” in the coherence
transformation processing and show that the evaluations of them are
reduced to single-letter formula: the coherence distillation is given by
the relative entropy of coherence (or in other words, we give the
relative entropy of coherence its operational interpretation) and the

Thursday, July 30, 2015 2:30 pm - 3:30 pm EDT (GMT -04:00)

Christoph Simon: Extending the quantum domain with quantum optics

Christoph Simon, University of Calgary

Quantum optical systems are well suited for pushing the boundaries of quantum physics. Two big goals in this context are the creation of entanglement over long distances and the observation of quantum effects on macroscopic scales. I will describe various theoretical and some experimental work in these directions.

Frank Wilhelm-Mauch, Universität des Saarlandes, Germany

Readout plays a central role in most quantum information protocols, notably in fault tolerance. While the readout of supercondcuting qubits operating in the microwave regime has reached exquisite performance using Josephson Parametric Amplifiers, these ask for large technological overhead that is difficult to scale down. We will show how a recently introduced microwave photon counter, the Josephson Photomultiplier JPM can be used for qubit readout with much less overhead and even elementary data processing on chip.

Tuesday, June 9, 2015 2:00 pm - 3:00 pm EDT (GMT -04:00)

Erik Woodhead: Prepare-and-measure quantum key distribution

Erik Woodhead, The Institute of Photonic Sciences, Spain

Quantum key distribution (QKD) can be implemented in both so-called
entanglement-based (EB) and prepare-and-measure (PM) configurations. There is a certain degree of equivalence between EB and PM schemes from the point of view of security analysis that has been heavily exploited in the literature over the last fifteen years or so, where a given PM protocol is reduced to an equivalent EB protocol (following the BBM92 argument) whose security is then proved.

Monday, June 22, 2015 2:30 pm - 3:30 pm EDT (GMT -04:00)

Tommaso Calarco: Steering many-body quantum dynamics

Tommaso Calarco, University of Ulm

Quantum technologies are based on the manipulation of individual degrees of freedom of quantum systems with exquisite precision. Achieving this in a real environment requires pushing to the limits the ability to control the dynamics of quantum systems of increasing complexity. Optimal control techniques are known to enable steering the dynamics of few-body systems in order to prepare a desired state or perform a desired unitary transformation.

Monday, June 15, 2015 2:30 pm - 3:30 pm EDT (GMT -04:00)

Mario Berta: Quantum Coding with Finite Resources

Mario Berta, California Institute of Technology

The quantum capacity of a memoryless channel is often used as a single figure of merit to characterize its ability to transmit quantum information coherently. The capacity determines the maximal rate at which we can code reliably over asymptotically many uses of the channel. We argue that this asymptotic treatment is insufficient to the point of being irrelevant in the quantum setting where decoherence severely limits our ability to manipulate large quantum systems in the encoder and decoder.

Tuesday, June 23, 2015 3:00 pm - 4:00 pm EDT (GMT -04:00)

Matthew McKague: Interactive proofs for BQP via self-test graph states

Matthew McKague, University of Otago, New Zealand

Is it possible to check a quantum computer's work? A quantum computation leaves behind no transcript, and for problems outside nondeterministic polynomial time (NP), it is not immediately clear whether we can verify that a quantum computation has been one correctly. Interactive proofs and self-testing offer a means of doing so.

Marzio Pozzuoli, RuggedCom

Abstract:
In 2001 RuggedCom was a fledging startup. A decade later it was bought by Siemens for nearly half a billion dollars. Mr. Pozzuoli, its founder, will discuss its path to success and the role played in that success by the Canadian experience and the strategies outlined in Geoffrey Moore’s iconic book “Crossing the Chasm”.

Biography:

Seminar

Marco Piani: An operational approach to the study of quantum correlations exploiting convex optimization