High Frequency Acousto-electric Single Photon Source
  We propose a single optical photon source for quantum cryptography based on the acousto-electric effect. Surface acoustic waves (SAWs) propagating through a quasi-one-dimensional channel have been shown to produce packets of electrons which reside in the SAW minima and travel at the velocity of sound. In our scheme these electron packets are injected into a p-type region, resulting in photon emission. Since the number of electrons in each packet can be controlled down to a single electron, a stream of single (or N) photon states, with a creation time strongly correlated with the driving acoustic field, should be generated. 
C. L. Foden (1), V. I. Talyanskii (2), G. J. Milburn (3), M. L.   Leadbeater (1) and M. Pepper (1 and 2) ((1) Cambridge Rese...