Benchmarking a quantum teleportation protocol in superconducting circuits using tomography and an entanglement witness

• Published in: Physical review letters Vol. 108; no. 4; p. 040502
• Main Authors: Baur, M, Fedorov, A, Steffen, L, Filipp, S, da Silva, M P, Wallraff, A
• Format: Journal Article
• Language: English
• Published: United States 24.01.2012
• ISSN: 1079-7114
• DOI: 10.1103/physrevlett.108.040502

Teleportation of a quantum state may be used for distributing entanglement between distant qubits in quantum communication and for quantum computation. Here we demonstrate the implementation of a teleportation protocol, up to the single-shot measurement step, with superconducting qubits coupled to a microwave resonator. Using full quantum state tomography and evaluating an entanglement witness, we show that the protocol generates a genuine tripartite entangled state of all three qubits. Calculating the projection of the measured density matrix onto the basis states of two qubits allows us to reconstruct the teleported state. Repeating this procedure for a complete set of input states we find an average output state fidelity of 86%.