Past Quantum Field Theory Seminar

4 February 2014
12:00
to
13:30
Shahn Majid (Queen Mary and Oxford)
Abstract
The talk is based on my paper with E. Beggs appearing in Class. Quantum Gravity. Working within a bimodule approach to noncommutative geometry, we show that even a small amount of noncommutativity drastically constrains the moduli space of noncommutative metrics. In particular, the algebra [x,t]=x is forced to have a geometry corresponding to a gravitational source at x=0 so strong that even light cannot escape. This provides a non-trivial example of noncommutative Riemannian geometry and also serves as an introduction to some general results.
  • Quantum Field Theory Seminar
21 January 2014
12:00
to
13:30
Mathew Pugh (Cardiff)
Abstract
The modular invariant partition functions for SU(2) and SU(3) conformal field theories have been classified. The SU(2) theory is closely related to the preprojective algebras of Coxeter-Dynkin quivers. The analogous finite dimensional superpotential algebras, which we call almost Calabi-Yau algebras, associated to the SU(3) invariants will be discussed.
  • Quantum Field Theory Seminar
21 May 2013
12:00
Ivette Fuentes (Nottingham)
Abstract
Cutting-edge experiments in quantum communications are reaching regimes where relativistic effects can no longer be neglected. For example, there are advanced plans to use satellites to implement teleportation and quantum cryptographic protocols. Relativistic effects can be expected at these regimes: the Global Positioning System (GPS), which is a system of satellites that is used for time dissemination and navigation, requires relativistic corrections to determine time and positions accurately. Therefore, it is timely to understand what are the effects of gravity and motion on entanglement and other quantum properties exploited in quantum information. In this talk I will show that entanglement can be created or degraded by gravity and non-uniform motion. While relativistic effects can degrade the efficiency of teleportation between moving observers, the effects can also be exploited in quantum information. I will show that the relativistic motion of a quantum system can be used to perform quantum gates. Our results, which will inform future space-based experiments, can be demonstrated in table-top experiments using superconducting circuits.
  • Quantum Field Theory Seminar

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