Abstract

In our work we discuss the possibility of using sets of non-orthogonal states for the quantum communication purposes. In particular, we focus our attention to sets of coherent states of simple harmonic oscillator. The signal we want to communicate is represented as a string of independent coherent states. We show that using only a pair of non-perfectly distinguishable coherent states an information compression could be achieved without the block coding, for example, by simple duplicating certain states in the sequence. The coherent states used for encoding can be weak, with average number of photons less then unity. We also discuss a block coding using binary sequences of coherent states demonstrating a significant difference from the classical coding and possibility to treat errors of state determination as usual errors induced by the noise of the transmission line.

© 2000 IEEE