====== Quantum Information Processing by Weaving Quantum Talbot Carpets ====== Data: Sexta-Feira 29/08/2014, Sala A5-01, 11 am\\ Palestrante: Osvaldo J. Farías (CBPF)\\ Título: Quantum Information Processing by Weaving Quantum Talbot Carpets\\ Resumo: Single photon interference due to the passage through a periodic grating is considered in a novel proposal for codifying D-dimensional qudits in the spatial degrees of freedom of light. Free space propagation naturally implements basic single qudit gates by means of the Talbot effect: an intricate time-space carpet of light in the near field of diffraction. Adding a diagonal phase gate, we show that a complete set of single qudit gates can be implemented. We then introduce a spatially-dependent beam splitter, which allows for measurement of the spatial qudits and implementation of controlled operations between two photons. A new form of universal quantum information processing can then be implemented with linear optics and ancilla photons. ~~DISCUSSION~~