The working principle of a time multiplexing detector: A single pulse of photons is split and recombined with various time delays producing a train of pulses with less than one photon per pulse. These pulses are send onto avalanche photo diodes producing 'click' or 'no-click' events. Counting the number of clicks gives information about the number of photons present in the initial pulse, but the exact relation between photon number distributions and measured click-statistics is complex because the click statistics are influenced by the number of beam splitters, the detector response functions and the losses in the system.
Scientists in the group of Christine Silberhorn in Paderborn and the group of Werner Vogel in Rostock have demonstrated a new method to identify nonclassical correlations between two parties sharing a quantum state. The method allows to characterize quantum states and resources in a simple and straight forward way. The results are published in Uncovering Quantum Correlations with Time-Multiplexed Click Detection, Phys. Rev. Lett. 115, 023601…
Die UNESCO hat 2015 zum “Internationalen Jahr des Lichts und der lichtbasierten Technologien” erklärt. Es steht unter dem Motto „Licht für Wandel“ und soll an die Bedeutung von Licht als elementare Lebensvoraussetzung erinnern sowie den gesellschaftlichen Nutzen der wissenschaftlichen Erkenntnisse über das Licht, z. B. in der Medizin oder im Bereich Kommunikation, ins Bewusstsein rücken.
In a joint cooperation of several research groups (including the IQO group), quantum teleportation over up to 25 km long fiber links and coupling to a solid state memory were demonstrated. Key results are now published in Nature Photonics.
Quantum networks pose high requirements on photon pair sources in terms of brightness, purity and integrability with other devices. We implemented a source in the lab that combines a number of desirable properties to fulfil those requirements to a high degree.
Quantum networks pose high requirements on photon pair sources in terms of brightness, purity and integrability with other devices. We implemented a source in the lab that combines a number of desirable properties to fulfil those requirements to a high degree.
