2008/06/04 by G. Pfanner, Pfanner, Gernot, Marek Seliger +3
Engineering · Computer Science · Physics and Astronomy · #Photonic and Optical Devices #Quantum Information and Cryptography #Mechanical and Optical Resonators
paper · pdf · doi:10.48550/arxiv.0806.0761
We theoretically investigate the production of polarization-entangled photons through the biexciton cascade decay in a single semiconductor quantum dot. To accomplish a high degree of entanglement, despite the exciton finestructure splitting, one must either energetically align the two exciton states by means of external fields or erase the which-path information by post-selecting photons within the correct frequency range. Here we show that in the latter scheme, as well as in related proposals, the photon state becomes deteriorated through dephasing processes in the solid, and the degree of entanglement remains low despite filtering.