  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.
