Quantum Measurements and Operations for Criptography and Information Processing

Review of recent experimental studies on Foundations of Quantum Mechanics and Quantum Information at “Carlo Novero” lab at IENGF

aula dottorato - GIOVedì 3 FEBBRAIO ore 15.30

Born in Turin (Italy) Nov. 17 1967
"laurea" degree 1990 (University of Turin)
PhD 1994 (University of Turin)
Worked at CERN (Geneva) 1994-1995, Lyon University (FR) 1995-1996, Grenoble University
1996-1998, IENGF since 1998
Actually permanent researcher at IENGF

He has published more than 50 papers on international scientific journals. Today his activity concerns foundations of quantum mechanics and quantum information.

Marco Genovese
  In this talk I will review some recent experimental progresses concerning Foundations of Quantum Mechanics and Quantum Information obtained in our Quantum Optics laboratory at IENGF.
More in details, after a short presentation of the lab “Carlo Novero”, I will present the results of an experiment where a conditioned unitary transformation (90° polarization rotation) is performed at single-photon level. The transformation is realized by rotating polarization for one of the photons of a polarization-entangled biphoton state (signal photon) by means of a Pockel's cell triggered by the detection of the other (idler) photon after polarization selection. As a result, polarization degree for the signal beam changes from zero to the value given by the idler detector quantum efficiency.
This scheme finds various applications to quantum communication protocols, furthermore it can also be used for developing a new method of absolute quantum efficiency calibration. We present a comparison of the results obtained with this scheme and with traditional calibration of photodetectors with biphotons.
I will then discuss an experiment where entanglement in type II PDC emission is restored by propagation in fiber, namely the effect of “deterioration” of wave packet in fiber propagation is used for re-establishing indistinguishability and entanglement.
Furthermore, I will hint at a recent experiment addressed to clarify the issue of which wave-particle observables are really to be considered when discussing wave particle duality. It realises a theoretical proposal of Agarwal et al., overcoming limitations of a former experiment.
Finally, I will rapidly sketch a set-up under realisation for codification in 4 dimensional Hilbert space.