Single-photon-interference communication equivalent to Bell-state-basis cryptographic quantum communication - art. no. 054303

We propose a single-photon interferometer which provides cryptographic quan tum communication equivalent to that obtained using a pair of polarization entangled photon twins as a carrier [Phys. Rev. A 60, 157 (1999)]. Instead of manipulating and measuring the internal states of entangled photon twins , cryptographic quantum communication is possible by manipulating a single photon in an extended interferometer. The use of the single-photon interfer ometer offers significant experimental advantages compared to our previous approach.