A quantum Fredkin gate

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Author(s)
Patel, Raj B
Ho, Joseph
Ferreyrol, Franck
Ralph, Timothy C
Pryde, Geoff J
Year published
2016
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Show full item recordAbstract
Minimizing the resources required to build logic gates into useful processing circuits is key to realizing quantum
computers. Although the salient features of a quantum computer have been shown in proof-of-principle
experiments, difficulties in scaling quantum systems have made more complex operations intractable. This is
exemplified in the classical Fredkin (controlled-SWAP) gate for which, despite theoretical proposals, no quantum
analog has been realized. By adding control to the SWAP unitary, we use photonic qubit logic to demonstrate
the first quantum Fredkin gate, which promises many applications in quantum information ...
View more >Minimizing the resources required to build logic gates into useful processing circuits is key to realizing quantum computers. Although the salient features of a quantum computer have been shown in proof-of-principle experiments, difficulties in scaling quantum systems have made more complex operations intractable. This is exemplified in the classical Fredkin (controlled-SWAP) gate for which, despite theoretical proposals, no quantum analog has been realized. By adding control to the SWAP unitary, we use photonic qubit logic to demonstrate the first quantum Fredkin gate, which promises many applications in quantum information and measurement. We implement example algorithms and generate the highest-fidelity three-photon Greenberger-Horne-Zeilinger states to date. The technique we use allows one to add a control operation to a black-box unitary, something that is impossible in the standard circuit model. Our experiment represents the first use of this technique to control a twoqubit operation and paves the way for larger controlled circuits to be realized efficiently.
View less >
View more >Minimizing the resources required to build logic gates into useful processing circuits is key to realizing quantum computers. Although the salient features of a quantum computer have been shown in proof-of-principle experiments, difficulties in scaling quantum systems have made more complex operations intractable. This is exemplified in the classical Fredkin (controlled-SWAP) gate for which, despite theoretical proposals, no quantum analog has been realized. By adding control to the SWAP unitary, we use photonic qubit logic to demonstrate the first quantum Fredkin gate, which promises many applications in quantum information and measurement. We implement example algorithms and generate the highest-fidelity three-photon Greenberger-Horne-Zeilinger states to date. The technique we use allows one to add a control operation to a black-box unitary, something that is impossible in the standard circuit model. Our experiment represents the first use of this technique to control a twoqubit operation and paves the way for larger controlled circuits to be realized efficiently.
View less >
Journal Title
Science Advances
Copyright Statement
© The Author(s) 2016. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (https://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted, non-commercial use, distribution and reproduction in any medium, providing that the work is properly cited.
Subject
Quantum Information, Computation and Communication
Quantum Optics