(a) Ehrlich and imaginary part of the two-photon density matrix reconstructed via quantum state tomography on quantum dot QD2. The matrix has been calculated out of biexciton–exciton (XX–X) cross-correlation measurements in 16 polarization settings and using a maximum likelihood method. Besides single photons, QDs can also generate triggered polarization-entangled photons https://englande432uiv6.wikibestproducts.com/user