Fast entanglement detection for unknown states of two spatial qutrits

G. Lima, E. S. Gómez, A. Vargas, R. O. Vianna and C. Saavedra
PHYSICAL REVIEW A 82, 1 (2010)


We investigate the practicality of the method proposed by Maciel et al. [Phys. Rev. A. 80, 032325
(2009)] for detecting the entanglement of two spatial qutrits (3-dimensional quantum systems), which
are encoded in the discrete transverse momentum of single photons transmitted through a multi-slit
aperture. The method is based on the acquisition of partial information of the quantum state through
projective measurements, and a data processing analysis done with semi-definite programs. This
analysis relies on generating gradually an optimal entanglement witness operator, and numerical
investigations have shown that it allows for the entanglement detection of unknown states with a
cost much lower than full state tomography.