Events

Extended nonlocal games from quantum-classical

Vincent Russo, IQC

Several variants of nonlocal games have been considered in the study of quantum entanglement and nonlocality. In this talk, we shall consider two such variants called quantum-classical games and extended nonlocal games. The players, Alice and Bob, may play the game according to various classes of strategies. An entangled strategy is one in which Alice and Bob use quantum resources in the form of a shared quantum state and sets of measurements. One may ask whether the dimension of the shared state makes a difference in how well the players can perform using an entangled strategy.

Perfect embezzlement of entanglement

Van Dam and Hayden introduced the concept of approximate embezzlement of entanglement. Even if one allows infinite dimensional resource spaces but requires a bipartite tensor product structure of the resource space, perfect embezzlement is still impossible. But in the commuting operator framework perfect embezzlement is possible. We then introduce unitary correlation sets and relate these ideas to the conjectures of Connes and Tsirelson.

Practical continuous variable quantum communication in fibre and free space systems

Christoph Marquardt, Max Planck Institute for the Science of Light

I will review our recent activities in continuous variable QKD that aims for the deployment of QKD equipment compatible with current telecom standards and research in satellite QKD that will make it possible to bridge long distances. In optical fibre systems continuous variable quantum cryptography reaches GHz speed and offers efficient integration with known telecommunication techniques, especially in short inner-city or data center links. Sending and receiving components, including quantum random number generators, can be efficiently built in integrated components. Optical free space communication is a reliable means to transmit classical and quantum information. Free space links offer ad-hoc establishment in intra-city communication, air-to-ground or satellite-to-ground scenarios.

Metal-oxide-semiconductor (MOS) Si quantum dots

Greg Holloway, IQC

Electrostatically defined quantum dots provide a flexible implementation for scalable spin-based quantum information processing. Recently Si has emerged as a promising platform for these systems, due to its long electron spin coherence times, and its compatibility with numerous fabrication processes. In this talk I will give a detailed description of the device architecture, as well as a description of transport through Si quantum dots.

Efficient Fault-Tolerant Quantum Computing

Martin Suchara, AT&T Labs Research

Quantum error correction presents some of the most significant and interesting challenges that must be resolved before building an efficient quantum computer. Quantum error correcting codes allow to successfully run quantum algorithms on unreliable quantum hardware. Because quantum hardware suffers from errors such as decoherence, leakage or qubit loss, and these errors corrupt delicate quantum states rather than binary information, the known error correction techniques are complex and have a high overhead. 

A proof of the quantum data processing inequality with a combinatorial flavour

Ashwin Nayak, Institute for Quantum Computing

The quantum data processing inequality (equivalently, the strong sub-additivity of von Neumann entropy) is a cornerstone of quantum information theory.  It has been proven in numerous ways, each proof highlighting different aspects of the property.

Quantum Engineering of Superconducting Qubits

William Oliver, Massachusetts Institute of Technology

Superconducting qubits are coherent artificial atoms assembled from electrical circuit elements and microwave optical components. Their lithographic scalability, compatibility with microwave control, and operability at nanosecond time scales all converge to make the superconducting qubit a highly attractive candidate for the constituent logical elements of a quantum information processor. 

Contextuality as a resource for quantum computation

Juan Bermejo Vega

A central question in quantum computation is to identify the resources that are responsible for quantum speed-up. Quantum contextuality has been recently shown to be a resource for quantum computation with magic states for odd-prime dimensional qudits and two-dimensional systems with real wavefunctions. The phenomenon of state-independent contextuality poses a priori an obstruction to characterizing the case of regular qubits, the fundamental building block of quantum computation.

Title TBA

If you're coming from the Lazaridis Centre, take the 11:35am shuttle from QNC to RAC1, and they can return to QNC from RAC1 @ 1:15pm.

A light lunch will be provided.

SIC-POVMs and algebraic number theory

John Yard, Institute for Quantum Computing

SIC-POVMs (Symmetric Informationally Complete Positive Operator-Valued Measures) are certain extremal rank-1 projective measurements corresponding to maximal sets of complex equiangular lines as well as to minimal complex projective 2-designs. They are conjectured to exist in every finite-dimensional complex Hilbert space as orbits of generalized Pauli groups.