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Quantum computation with coherent states

Alexei Gilchrist, Timothy C. Ralph, William J. Munro, Gerard J Milburn

Published Jan 1, 2003• 7 citations
OpenAlex

Abstract

We extend a previous proposal for performing deterministic quantum computation using coherent states and linear optics by examining a new version of one of the gates which offers several advantages.

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We suggest an efficient scheme for quantum computation with linear optical elements, where the qubits are encoded in single photon states. The scheme reduces the resources required per logical gate by several orders of magnitude, compared to an earlier proposal of Knill, Laflamme, and Milburn, while the resource overhead per gate is independent of the length of the computation. A central feature of the scheme, enabling these improvements, is the prior construction of a "linked" photon state designed according to the particular quantum circuit one wishes to process. Once this state has been successfully prepared, the computation is pursued deterministically by a sequence of teleportation steps.