Transverse entanglement of biphotons

Language
en
Document Type
Article
Issue Date
2014-02-11
Issue Year
2013
Authors
Just, Felix
Cavanna, Andrea
Chekhova, Maria V.
Leuchs, Gerd
Editor
Abstract

We measure the transverse entanglement of photon pairs on their propagation from the near to the far field of spontaneous parametric down-conversion (SPDC). The Fedorov ratio, depending on the widths of conditional and unconditional intensity measurements, is shown to be only able to characterize entanglement in the near and far field zones of the source. Therefore we also follow a different approach. By evaluating the first-order coherence of a subsystem of the state we can quantify its entanglement. Unlike previous measurements, which determine the Fedorov ratio via intensity correlations, our setup is sensitive to both phase and modulus of the biphoton state and thus always grants experimental access to the full transverse entanglement of the SPDC state. It is shown theoretically that this scheme represents a direct measurement of the Schmidt number.

Journal Title
New Journal of Physics
Volume
15
Issue
8
Citation
New Journal of Physics 15.8 (2013): 06.02.2014 <http://iopscience.iop.org/1367-2630/15/8/083015>
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