Quantum communications and beyond.
We introduce the concept of encoding and manipulation of information on single photons. This is exploited in the technique of quantum cryptography to distribute random bit strings in a secure way. More general quantum information processing requires a conditional interaction between separate photons. This can be achieved by exploiting the interference between two photons at a beam-splitter and the non-linearity inherent in detection. As yet the efficiency of such gates is low.
Rarity
J G
JG
Department of Electrical and Electronic Engineering, University of Bristol, Woodland Road, Bristol BS8 1UB, UK.