Repeat-until-success cubic phase gate for universal continuous-variable quantum computation

by Kevin Marshall, Raphael Pooser, George Siopsis, Christian Weedbrook

Repeat-until-success scheme in which a pulsed resource state remains in a cavity until a photon detection is registered.


To achieve universal quantum computation using continuous variables, one needs to jump out of the set of Gaussian operations and have a non-Gaussian element, such as the cubic phase gate. However, such a gate is currently very difficult to implement in practice. Here we introduce an experimentally viable “repeat-until-success” approach to generating the cubic phase gate, which is achieved using sequential photon subtractions and Gaussian operations. We find that our scheme offers benefits in terms of the expected time until success, as well as the fact that we do not require any complex off-line resource state, although we require a primitive quantum memory.

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Publication Citation

Physical Review A 2015 91 (3)
DOI: 10.1103/PhysRevA.91.032321