Quantum Interference of Identical Photons from Remote Quantum Dots
Photonic quantum technology provides a viable route to quantum communication,
quantum simulation, and quantum information processing. Recent progress has
seen the realisation of boson sampling using 20 single-photons and quantum key
distribution over hundreds of kilometres. Scaling the complexity requires
photonic architectures containing a large number of single photons, multiple
photon-sources and photon-counters. Semiconductor quantum dots are bright and
fast sources of coherent single-photons. For applications, a significant
roadblock is the poor quantum coherence upon interfering single photons created
by independent quantum dots. Here, we demonstrate two-photon interference with
near-unity visibility using photons from remote quantum dots. Exploiting the
quantum interference, we demonstrate a photonic controlled-not circuit and a
high-fidelity entanglement between photons of different origins. Our results
provide a long-awaited solution to the challenge of creating coherent
single-photons in a scalable way. In the near future, they point to a
demonstration of quantum advantage using quantum-dot single photons and an
implementation of device-independent quantum key distribution.
Authors
Liang Zhai, Giang N. Nguyen, Clemens Spinnler, Julian Ritzmann, Matthias C.Löbl, Andreas D. Wieck, Arne Ludwig, Alisa Javadi, Richard J. Warburton