FLAP Journal 2018 Journal Article
Higher-Radix Chrestenson Gates for Photonic Quantum Computation.
- Kaitlin N. Smith
- Tim LaFave
- Duncan L. MacFarlane
- Mitchell A. Thornton
A recently developed four-port coupler used in optical signal processing ap- plications is shown to be equivalent to a Chrestenson operator, or gate, in radix-4 quantum information processing (QIP) applications. The radix-4 qudit is implemented as a location-encoded photon incident on one of the four ports of the coupler. The quantum informatics transfer matrix is derived for the device based upon the conservation of energy equations when the coupler is employed in a classical sense in an optical communications environment. The resulting transfer matrix is the radix-4 Chrestenson transform, and this operator is capa- ble of placing a radix-4 qudit in a state of maximal superposition. This result indicates that a new practical device is available for use in the implementa- tion of radix-4 QIP applications or in the construction of a radix-4 quantum computer.