Quantum Information Processing and its Linear Optical Implementation

Yuta Okubo

雄太 大久保

Deepesh Singh

Alexander V. Sergienko, David S. Simon, Shuto Osawa

David S. Simon, Casey A. Fitzpatrick, Alexander V. Sergienko

The concept of directionally unbiased optical multiports is introduced, in which photons may reflect back out the input direction. A linear-optical implementation is described, and the simplest three-port version studied. Symmetry arguments demonstrate potential for unusual quantum information processing applications. The devices impose group structures on two-photon entangled Bell states and act as universal Bell-state processors to implement probabilistic quantum gates acting on state symmetries. These multiports allow optical scattering experiments to be carried out on arbitrary undirected graphs via linear optics and raise the possibility of linear-optical information processing using group structures formed by optical qudit states.

Jacques Carolan, C. Harrold, Chris Sparrow +13 more

Linear optics underpins fundamental tests of quantum mechanics and quantum technologies [1], as well as native protocols such as boson sampling. Here we experimentally demonstrate the longstanding goal of a single reprogrammable linear optical circuit that is sufficient to implement all possible linear optical protocols up to the size of that circuit [2].