Quantum teleportation of four-dimensional qudits

A protocol for the teleportation of arbitrary quantum states of four-dimensional qudits is presented. The qudit to be teleported is encoded in the combined state of two ensembles of atoms placed in a cavity at the sender’s side. The receiver uses a similar setup, with his atoms prepared in a particular initial state. The teleportation protocol then consists of adiabatic mapping of the ensemble states onto photonic degrees of freedom, which are then directed onto a specific beam splitter and detection setup. For part of the measurement outcome, the qudit state is fully transferred to the receiver. Other detection events lead to partial teleportation or failed teleportation attempts. The interpretation of the different detection outcomes and possible ways of improving the full teleportation probability are discussed.

Figure 1

Schematic representation of the teleportation setup. On Alice’s side, two ensembles of atoms encode the state to be teleported, and on Bob’s side, the ensembles are prepared in a particular initial state in a similar setup. The inset shows the level configuration of each atom in the ensembles. Using adiabatic state transfer, both parties then map the ensemble states coherently to photonic DOF, which enter the beam splitter setup. The setup for the mapping between ensembles and light is similar to the experiment reported in [28]. The initial state prepared by Alice enters in the top-left corner. Bob’s state enters in the bottom-right corner. The detectors are placed in the two other corners. The input photon states are passed through polarization beam splitters (PBS) to separate the two photon modes, and the outputs of the PBSs are recombined on beam splitters (BS). The output modes of the beam splitters are detected by four photon detectors $D_{L_1}$, $D_{L_2}$, $D_{R_1}$, and $D_{R_2}$.