G. Lima, F. A. Torres-Ruiz, L. Neves, A. Delgado, C. Saavedra and S. Pádua
OPTICS COMMUNICATION 281 (2008)
In a recent letter [L. Neves, G. Lima, J.G. Aguirre Gomez, C.H. Monken, C. Saavedra, S. Padua, Phys. Rev. Lett. 94 (2005) 100501], we presented a scheme for generating pure entangled states of spatial qudits (D-dimensional quantum systems) by using the momentum transverse correlation of the parametric down-converted photons. In this work, we discuss a generalization of this process to enable the creation of mixed states. With the technique proposed we experimentally generated a mixture of two spatial qubits. (C) 2008 Elsevier B.V. All rights reserved.