Homodyne tomography characterization and nonlocality of a dual-mode optical qubit.
A single photon, delocalized over two optical modes, is characterized by means of quantum homodyne tomography. The reconstructed four-dimensional density matrix extends over the entire Hilbert space and thus reveals, for the first time, complete information about the dual-rail optical quantum bit as a state of the electromagnetic field. The experimental data violate the Bell inequality albeit with a loophole similar to the detection loophole in photon counting experiments.
Babichev
S A
SA
Fachbereich Physik, Universität Konstanz, D-78457 Konstanz, Germany.
Appel
J
J
Lvovsky
A I
AI