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arXiv:0911.5115 · Physical Review A

Versatile source of polarization-entangled photons

Andreas Maser, Ralph Wiegner, U. Schilling, C. Thiel, Joachim von Zanthier

Published May 24, 2010• 9 citations
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Abstract

We propose a method for the generation of a large variety of entangled states, encoded in the polarization degrees of freedom of $N$ photons, within the same experimental setup. Starting with uncorrelated photons, emitted from $N$ arbitrary single-photon sources, and using linear optical tools only, we demonstrate the creation of all symmetric states (e.g., GHZ and $W$ states), as well as all symmetric and nonsymmetric total angular momentum eigenstates of the $N$-qubit compound.

DOI
10.1103/physreva.81.053842

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Abstract Single-photon sources based on semiconductor quantum dots find several applications in quantum information processing due to their high single-photon indistinguishability, on-demand generation, and low multiphoton emission. In this context, the generation of entangled photons represents a challenging task with a possible solution relying on the interference in probabilistic gates of identical photons emitted at different pulses from the same source. In this work, we implement this approach via a simple and compact design that generates entangled photon pairs in the polarization degree of freedom. We operate the proposed platform with single photons produced through two different pumping schemes, the resonant excited one and the longitudinal-acoustic phonon-assisted configuration. We then characterize the produced entangled two-photon states by developing a complete model taking into account relevant experimental parameters, such as the second-order correlation function, Hong–Ou–Mandel visibility, multiphoton emission and pump laser filtering. Our source shows long-term stability and high quality of the generated entangled states, thus constituting a reliable building block for optical quantum technologies.