2008/05/08 by Gen Taguchi, Tatsuo Dougakiuchi, Nobuaki Yoshimoto +5 · 5 citations
Computer Science · Physics and Astronomy · #Orbital Angular Momentum in Optics #Quantum Information and Cryptography #Quantum Mechanics and Applications #quant-ph
paper · pdf · doi:10.1103/physreva.78.012307
published as Phys. Rev. A 78, 012307 (2008) · 19 pages, including 10 figures and 2 tables
arxiv created 2008/05/08 · openalex publication_date 2008/07/07 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We present an experimental study of the nonclassical correlations of a pair of spatial qubits formed by passing two down-converted photons through a pair of double slits. After confirming the entanglement generated in our setup by quantum tomography using separate measurements of the slit images and the interference patterns, we show that the complete Hilbert space of the spatial qubits can be accessed by measurements performed in a single plane between the image plane and the focal plane of a lens. Specifically, it is possible to obtain both the which-path and the interference information needed for quantum tomography in a single scan of the transversal distribution of photon coincidences. Since this method can easily be extended to multidimensional systems, it may be a valuable tool in the application of spatial qudits to quantum-information processes.