Experimental conversion of position correlation into polarization entanglement
Chithrabhanu Perumangatt, Alexander Lohrmann, Alexander Ling · Physical Review A · 2020
This paper presents a method to convert position correlation of photon pairs into polarization entanglement. This is achieved by individually manipulating the polarization state of photons generated in different parts of a nonlinear medium and coherently superposing them. This concept is experimentally demonstrated using photon pairs produced by spontaneous parametric down-conversion. The method is used to implement a compact source producing an observed photon-pair rate of $120\phantom{\rule{0.16em}{0ex}}000\phantom{\rule{4.pt}{0ex}}{\text{s}}^{\ensuremath{-}1}/\text{mW}$ with an entanglement fidelity of $0.991\ifmmode\pm\else\textpm\fi{}0.013$. This method can be extended to any photon-pair generation process with initial position correlation.