Full-Bloch-sphere teleportation of spinor Bose-Einstein condensates and spin ensembles

Abstract

Quantum teleportation is the transfer of quantum information between two locations by the use of shared entanglement. Current teleportation schemes broadly fall under one of two categories, either qubit or continuous-variable teleportation. Spin coherent states on spin ensembles can be teleported under the continuous-variable approximation for states with small deviations from a given polarization. However, for spin-coherent states with large deviations, no convenient teleportation protocol exists. Recently, we introduced a teleportation scheme where a spin-coherent state lying on the equator of the Bloch sphere is teleported between distant parties [A. N. Pyrkov and T. Byrnes, New J. Phys. 16, 073038 (2014)]. Here we generalize the protocol to a spin-coherent state with an arbitrary position on the Bloch sphere. Our proposed scheme breaks classical bounds based on communication in the unconditional case and quantum state estimation with postselection.