Application of process tomography to quantum teleportation

Three Ca-40 ions trapped in a linear Paul trap serve as a three-qubit register that can be manipulated by series of suitably tailored laser pulses. We implement deterministic quantum teleportation in the following way: First, we create a maximally entangled pair of ions that will be shared between the sending and the receiving party. Next, the third quantum bit is prepared in an arbitrary quantum state that will be teleported to the quantum bit of the receiver (the target). This is done by measuring the quantum bits of the sender in a basis of maximally entangled states and depending on the measurement result - applying one out of four unitary transformations to the target qubit. This teleportation protocol can be completely characterized by preparing six different input states and tomographically reconstructing the corresponding output states. The information obtained in this way is used for reconstructing the quantum process with the help of a maximum-likelihood technique.