A fundamental element of quantum information processing with photonic qubitsis the nonclassical quantum interference between two photons when they bunchtogether via the Hong-Ou-Mandel (HOM) effect. Ultimately, many such purephotons must be processed in complex interferometric networks, and for this itis essential to synchronize the arrival times of the flying photons preservingtheir purity. Here we demonstrate for the first time the HOM interference oftwo heralded, pure optical photons synchronized through two independent quantummemories. Controlled storage times up to 1.8 microseconds for about 90 eventsper second were achieved with purities sufficiently high for a negative Wignerfunction confirmed with homodyne measurements.
展开▼
