



@article {1364,
	title = {Fault-tolerant Quantum Communication with Minimal Physical Requirements},
	journal = {Physical Review Letters},
	volume = {96},
	year = {2006},
	month = {2006/2/23},
	abstract = {We describe a novel protocol for a quantum repeater which enables long distance quantum communication through realistic, lossy photonic channels. Contrary to previous proposals, our protocol incorporates active purification of arbitrary errors at each step of the protocol using only two qubits at each repeater station. Because of these minimal physical requirements, the present protocol can be realized in simple physical systems such as solid-state single photon emitters. As an example, we show how nitrogen vacancy color centers in diamond can be used to implement the protocol, using the nuclear and electronic spin to form the two qubits.
},
	doi = {10.1103/PhysRevLett.96.070504},
	url = {http://arxiv.org/abs/quant-ph/0410123v3},
	author = {L. Childress and J. M. Taylor and A. S. Sorensen and M. D. Lukin}
}
@article {1363,
	title = {Fault-tolerant quantum repeaters with minimal physical resources, and implementations based on single photon emitters},
	journal = {Physical Review A},
	volume = {72},
	year = {2005},
	month = {2005/11/28},
	abstract = {We analyze a novel method that uses fixed, minimal physical resources to achieve generation and nested purification of quantum entanglement for quantum communication over arbitrarily long distances, and discuss its implementation using realistic photon emitters and photonic channels. In this method, we use single photon emitters with two internal degrees of freedom formed by an electron spin and a nuclear spin to build intermediate nodes in a quantum channel. State-selective fluorescence is used for probabilistic entanglement generation between electron spins in adjacent nodes. We analyze in detail several approaches which are applicable to realistic, homogeneously broadened single photon emitters. Furthermore, the coupled electron and nuclear spins can be used to efficiently implement entanglement swapping and purification. We show that these techniques can be combined to generate high-fidelity entanglement over arbitrarily long distances. We present a specific protocol that functions in polynomial time and tolerates percent-level errors in entanglement fidelity and local operations. The scheme has the lowest requirements on physical resources of any current scheme for fully fault-tolerant quantum repeaters.
},
	doi = {10.1103/PhysRevA.72.052330},
	url = {http://arxiv.org/abs/quant-ph/0502112v1},
	author = {L. I. Childress and J. M. Taylor and A. S. Sorensen and M. D. Lukin}
}
