Abstract:
Quantum information is very different from its everyday classical counterpart:
it cannot be read without disturbance, it cannot be copied or broadcast at
all, but it can exist in superposition of classical states. Classical and
quantum information can perform together feats that neither could achieve
alone. This
talk surveys some of the most striking new applications of quantum mechanics
for information processing purposes, such as quantum cryptography, quantum
computing and quantum teleportation. Some of these applications are still
theoretical but others have been implemented.
Quantum computers take advantage of the superposition principle to allow exponentially many computations to be performed simultaneously in a single piece of hardware. In particular, this threatens most of the classical cryptographic schemes currently in use to protect confidential information. As a remedy, quantum cryptography exploits the unavoidable disturbance caused by any attempt at measuring quantum information to implement a cryptographic system that allows two people to communicate in absolute secrecy under the nose of an eavesdropper equipped with unlimited computing power. Quantum teleportation uses nonlocal effects of quantum mechanics to allow the transmission of quantum information with no need for a quantum channel at the time transmission actually occurs.
No previous background on quantum mechanics or cryptography will be expected from the audience.