Parametric downconversion and optical quantum gates: two’s company, four’s a crowd
Author(s)
Barbieri, M.
Weinhold, Till
Lanyon, B.
Gilchrist, A.
Resch, K.
Almeida, M.
White, A.
Griffith University Author(s)
Year published
2009
Metadata
Show full item recordAbstract
We show that the primary cause of errors in a broad class of optical quantum-logic gates are due to the higher-order photon terms in parametric downconversion sources. A model describing real-life imperfections in these entangling gates is presented and tested in an experiment where we entangle dependent photons from the same downconversion source using a controlled-z gate, and measure the state tomographically. We find good agreement between the modelled and measured results. Our investigations demonstrate that, although small, these noise terms are amplified by the intrinsic non-determinism of the gates. It is worth ...
View more >We show that the primary cause of errors in a broad class of optical quantum-logic gates are due to the higher-order photon terms in parametric downconversion sources. A model describing real-life imperfections in these entangling gates is presented and tested in an experiment where we entangle dependent photons from the same downconversion source using a controlled-z gate, and measure the state tomographically. We find good agreement between the modelled and measured results. Our investigations demonstrate that, although small, these noise terms are amplified by the intrinsic non-determinism of the gates. It is worth considering alternative schemes based on weak nonlinearities to see if they are more resilient to this degradation.
View less >
View more >We show that the primary cause of errors in a broad class of optical quantum-logic gates are due to the higher-order photon terms in parametric downconversion sources. A model describing real-life imperfections in these entangling gates is presented and tested in an experiment where we entangle dependent photons from the same downconversion source using a controlled-z gate, and measure the state tomographically. We find good agreement between the modelled and measured results. Our investigations demonstrate that, although small, these noise terms are amplified by the intrinsic non-determinism of the gates. It is worth considering alternative schemes based on weak nonlinearities to see if they are more resilient to this degradation.
View less >
Journal Title
Journal of Modern Optics
Volume
56
Issue
2-3
Subject
Atomic, molecular and optical physics
Atomic, molecular and optical physics not elsewhere classified
Quantum physics
Nanotechnology