Entanglement Swapping with Semiconductor-Generated Photons Violates Bell's Inequality.

Transferring entangled states between photon pairs is essential in quantum communication. Semiconductor quantum dots arc the leading candidate for generating polarization-entangled photons deterministically. Here we show for the first time swapping of entangled states between two pairs of photons emitted by a single dot. A joint Bell measurement heralds the successful generation of the Bell state psi+, yielding a fidelity of 0.81 +/- 0.04 and violating the CHSH and Bell inequalities. Our photon source matches atomic quantum memory frequencies, facilitating implementation of hybrid quantum repeaters.