Local encoding of classical information onto quantum states

Abstract

In this article we investigate the possibility of encoding classical information onto multipartite quantum states in the distant laboratory framework. We show that for all states generated by Clifford operations there always exists such an encoding; this includes all stabilizer states such as cluster states and all graph states. We also show local encoding for classes of symmetric states (which cannot be generated by Clifford operations). We generalize our approach using group theoretic methods introducing the unifying notion of pseudo Clifford operations. All states generated by pseudo Clifford operations are locally encodable (unifying all our examples), and we give a general method for generating sets of many such locally encodable states.

Acknowledgements

We are very grateful to Akimasa Miyake, Shashank Virmani, Masaki Owari, Toshio Ohshima and Terry Rudolph for stimulating discussions on this topic. This work was sponsored by the Asahi Glass Foundation and the Japan Society for the Promotion of Science.