Experimental quantum teleportation of a two-qubit composite system

Abstract

Quantum teleportation 1 , a way to transfer the state of a quantum system from one location to another, is central to quantum communication 2 and plays an important role in a number of quantum computation protocols 3-5 . Previous experimental demonstrations have been implemented with photonic 6-8 or ionic qubits 9,10 . Very recently long-distance teleportation 11,12 and open-destination teleportation 13 have also been realized. Until now, previous experiments 6-13 have only been able to teleport single qubits. However, since teleportation of single qubits is insufficient for a large-scale realization of quantum communication and computation 2-5 , teleportation of a composite system containing two or more qubits has been seen as a long-standing goal in quantum information science.Here, we present the experimental realization of quantum teleportation of a two-qubit composite system. In the experiment, we develop and exploit a six-photon interferometer to teleport an arbitrary polarization state of two photons. The observed teleportation fidelities for different initial states are all

Efficient Toffoli gates using qudits

“…The proposed heralded circuit represents a five-photon experiment. Such experiments are feasible, but difficult [10]. In the following section we propose an in principle demonstration requiring only three photons.…”

Experimental generation of an eight-photon Greenberger–Horne–Zeilinger state

“…Typical systems for two-photon-pair experiments use a frequency-doubled Ti:sapphire mode-locked laser as a pump, with a repetition rate of ~80 MHz, a pulse duration of ~150 fs, and an operating wavelength of ~400 nm. The improvement in moving from two-photon-pair to three-photon-pair experiments depends on the pump power being increased from 600 mW to 1 W through the use of a high-power continuouswave laser to pump the mode-locked laser 14 . However, the sixfold coincidence count rates under this pump power are still low, and it is difficult to increase the pump power further in order to manipulate more photon pairs.…”

Quantum-information splitting using multipartite cluster states

“…Quantum teleportation is a technique for transfer of information between parties, using a distributed entangled state and a classical communication channel [1]. It also serves as an elementary operation for a number of quantum communicational protocols and has been experimentally demonstrated for arbitrary single and two qubit systems using pairs of Bell states [2,3]. With better understanding of multipartite entanglement, several authors have devised protocols for teleportation using multiparticle entangled channels [4,5,6,7,8,9].…”