Creating Polarization-Entangled Photon Pairs from a Semiconductor Quantum Dot Using the Optical Stark Effect
Andreas Muller, Wei Fang, John R. Lawall, Glenn S. Solomon
An entangled photon pair is a purely nonclassical, inseparable state of two light quanta. Because of its atom-like properties, a semiconductor quantum dot is an ideal source of this light. However, entanglement in these 'artificial atoms' is generally precluded by the asym-metric quantum dot confinement and its associated fine-structure splitting. Here we show how an external field—in our case a near-resonant laser, fiber-coupled to the device—can erase the fine-structure splitting, thereby restoring entanglement. We measure the density matrix of the emitted two-photon state under various conditions; when symmetry is restored it satisfies well-known entanglement tests. Our approach applies to quantum dots with typical fine-structure splittings, demonstrating that discrete polarization-entangled photons can now be routinely produced in a semiconductor nanostructure.
, Fang, W.
, Lawall, J.
and Solomon, G.
Creating Polarization-Entangled Photon Pairs from a Semiconductor Quantum Dot Using the Optical Stark Effect, Science, [online], https://doi.org/10.1103/PhysRevLett.103.217402, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=901342
(Accessed December 7, 2023)