Research Article
Tailoring the Spatio-temporal Bandwidth of Biphotons via the Non-factorable Structure of Entanglement
@INPROCEEDINGS{10.1007/978-3-642-11731-2_1, author={L. Caspani and E. Brambilla and L. Lugiato and A. Gatti}, title={Tailoring the Spatio-temporal Bandwidth of Biphotons via the Non-factorable Structure of Entanglement}, proceedings={Quantum Communication and Quantum Networking. First International Conference, QuantumComm 2009, Naples, Italy, October 26-30, 2009, Revised Selected Papers}, proceedings_a={QUANTUMCOMM}, year={2012}, month={10}, keywords={Quantum entanglement Parametric Down-Conversion Biphoton correlation}, doi={10.1007/978-3-642-11731-2_1} }- L. Caspani
E. Brambilla
L. Lugiato
A. Gatti
Year: 2012
Tailoring the Spatio-temporal Bandwidth of Biphotons via the Non-factorable Structure of Entanglement
QUANTUMCOMM
Springer
DOI: 10.1007/978-3-642-11731-2_1
Abstract
We investigate the spatio-temporal structure of the biphoton entanglement in Parametric Down Conversion (PDC). In particular we study the biphoton amplitude at the output face of the nonlinear crystal (near-field) and we demonstrate its X-shaped geometry in the space-time dimensions, i.e. the non-factorability of the state with respect to spatial and temporal variables. Our analysis provides a precise and quantitative characterization of this structure in various regimes and types of phase matching of PDC. The key elements of novelty emerging from our analysis are the non-factorability of the state with respect to spatial and temporal variables, and the extreme relative localization of the entangled photons, both in space (few microns) and time (few femtoseconds). This extreme localization is connected to our ability to resolve the photon positions in the source near-field. The non factorability opens the possibility of tailoring the temporal entanglement by acting on the spatial degrees of freedom of twin photons.