Repeat-Until-Success Quantum Computing

Abstract

We demonstrate the possibility to perform distributed quantum computing using only single photon sources (atom-cavity-like systems), linear optics and photon detectors. The qubits are encoded in stable ground states of the sources. To implement a universal two-qubit gate, two photons should be generated simultaneously and pass through a linear optics network, where a measurement is performed on them. Gate operations can be repeated until a success is heralded without destroying the qubits at any stage of the operation. In contrast to other schemes, this does not require explicit qubit-qubit interactions, a priori entangled ancillas nor the feeding of photons into photon sources.

5 pages, 2 figures, v3: substantially revised, v4: typos corrected