Areas of Interest

Quantum teleportation and communication - An unknown quantum state can be deleted in one place and recreated in another effectively, "teleported" by using a supply of previously shared entangled quantum systems together with a short classical signal. Teleportation means that one can envisage distributed networks of quantum computers exchanging quantum information back and forth. Teleportation is also crucial to the implementation of quantum key distribution over arbitrary distances and to some other important quantum cryptographic protocols. Moreover, it plays a crucial role in a recent proposal for an efficient optical implementation of a quantum computer. Real world implementations of teleportation are necessarily imperfect, since perfect maximally entangled quantum systems are an idealisation which can only be approximated in practice. This means that the theory of entanglement purification is crucial for optimal practical teleportation, as is understanding the trade-offs between using quantum and classical resources for communication and storage. The QIP group has contributed significantly to the relevant theory and continues to be very active in these areas.