Current graduate students
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.
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.
Twisting the neutron wavefunction
Charles W. Clark, National Institute of Standards and Technology
Wave motions in water were already familiar in antiquity. The mathematical representation of waves in physics today is essentially the same as that first provided by d'Alembert and Euler in the mid-18th century. Yet it was only in the early 1990s that physicists managed to control a basic property of light waves: their capability of swirling around their own axis of propagation.
Post-Quantum Key Exchange for the Internet and the Open Quantum Safe Project
Douglas Stebila, McMaster University
Most public key cryptography algorithms used on the Internet are based on mathematical problems which could be broken by large-scale quantum computers. This motivates the field of post-quantum cryptography, which aims to construct public key cryptosystems that are believed to be secure even against quantum computers. Since a future quantum computer could retroactively break the confidentiality of today's communications, it is important to begin transitioning public key encryption and key exchange to quantum-resistant algorithms.
Matthew Graydon of the Department of Physics and Astronomy is defending his thesis:
Conical Designs and Categorical Jordan Algebraic Post-Quantum Theories
Matthew is supervised by Associate Professor Kevin Resch and Rob Spekkens (Perimeter Institute for Theoretical Physics).
Greg Holloway of the Department of Physics and Astronomy is defending his thesis:
Electron transport in semiconducting nanowires and quantum dots
Greg is supervised by Associate Professor Joanthan Baugh.
John Donohue of the Department of Physics and Astronomy is defending his thesis:
Ultrafast manipulation of single photons using dispersion and sum-frequency generation
John is supervised by Associate Professor Kevin Resch.
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.
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.
