The efficiencies of generating cluster states with weak nonlinearities

Sebastien G R Louis*, Kae Nemoto, W. J. Munro, T. P. Spiller

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


We propose a scalable approach to building cluster states of matter qubits using coherent states of light. Recent work on the subject relies on the use of single photonic qubits in the measurement process. These schemes can be made robust to detector loss, spontaneous emission and cavity mismatching but as a consequence the overhead costs grow rapidly, in particular when considering single photon loss. In contrast, our approach uses continuous variables and highly efficient homodyne measurements. We present a two-qubit scheme, with a simple bucket measurement system yielding an entangling operation with success probability 1/2. Then we extend this to a three-qubit interaction, increasing this probability to 3/4. We discuss the important issues of the overhead cost and the time scaling. This leads to a 'no-measurement' approach to building cluster states, making use of geometric phases in phase space.

Original languageEnglish
Article number193
JournalNew Journal of Physics
Publication statusPublished - 29 Jun 2007

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