The future of quantum information processing relies on realisation of efficient sources of single photons, the ideal carriers of quantum information. Parametric downconversion (PDC) is a promising route to create highly coherent, spectrally pure single photons for quantum photonics using versatility of group-velocity matching and tailored nonlinearities. We present a new technique of engineered nonlinear crystals, which simultaneously enhances single photon purity and heralding efficiencies. Our technique allows photon spectral purity to be free from the requirement for narrow band filtering which ultimately limits the heralding efficiency of our non-deterministic sources. We experimentally demonstrate 92.7% of single photon purity and heralding efficiency above 63% (directly measured with our 80% efficient superconducting nanowire detectors). We will describe how such sources, embedded into Sagnac interferometers can be used to generate ultrafast photon clusters entangled in the polarisation degree of freedom. The developed platform will benefit wide range of quantum-enhanced technologies utilising many-photon entanglement in scaled photonic networks.
|Publication status||Published - 25 Apr 2018|
|Event||Quantum Technologies 2018 - Strasbourg, France|
Duration: 23 Apr 2018 → 25 Apr 2018
|Conference||Quantum Technologies 2018|
|Period||23/04/18 → 25/04/18|
Kundys, D., Graffitti, F., Proietti, M., Barrow, P., Pickston, A., Ringbauer, M., & Fedrizzi, A. (2018). Pure photon sources for many-photon cluster states generation: Oral presentation. Abstract from Quantum Technologies 2018, Strasbourg, France.