Thursday, 27 April 2017

Day 3 of the Bristol Quantum Information Technologies (BQIT) workshop

Almut Beige (University of Leeds) and her talk "from optical cavities to cavity-fibre networks"

BQIT:17's third and final day saw the workshop draw to a close with another sunny day of talks on detectors, hybrid platforms and integrated photonics.

Kicking things off was Sae Woo Nam from NIST. Sae Woo explained two projects around the subject of superconducting nanowire single photon detectors (SNSPDs): one which showed a detection efficiency when used in practice of over 93%, and another on SNSPDs integrated into waveguides. He finished talking about some work with Dave Wineland integrating these detectors with ion traps. University of Münster's Wolfram Pernice followed this by speaking about developing SNSPDs which are capable of detecting single photons in plane, making them suitable for waveguides.

The first solid state & hybrid systems session began with Almut Beige from the University of Leeds, who explained how we can better understand how to couple optical cavities from working out the Hamiltonian of a beam splitter. She was followed by the University of Bristol's own Ruth Oulton discussing her group's work using a quantum dot to switch the polarisation of a single photon, where they were able to achieve 80% efficiency. Sven Hofling from the University of Wurzburg concluded this segment talking about using quantum dots as single photon sources.

After lunch, the integrated quantum photonics section started with Sébastien Tanzilli from the University of Nice, who explained their recent results on generating two-photon N00N states. These states were then used to measure chromatic dispersion in an optical fibre with more than twice the precision even though there were sixty times as fewer photons. This was followed by the Raffaele Santagati from the University of Bristol. Raffaele introduced WAVES, a witness assisted eigenvalue solver capable of successfully estimating phase with an error of ​ radians, even in the presence of noise.

The final talks of the workshop formed our second session on hybrid & solid state systems. Jason Smith from the University of Oxford, spoke about coupling photons in microcavities with NV centres in nanodiamond, producing a 97% purity room temperature single photon source. Finally, Peter Humphreys from Delft University of Technology explained work on using entanglement distillation to create better entangled NV centres, as a step towards a large scale quantum network following their 13km Bell violation.

Proceedings were closed by Professor John Rarity FRS, director of QET Labs.

Thank you to everyone who joined us this year and for helping to make our workshop a success.

Save the date for next year's BQIT workshop: 18-20 April 2018

Our workshop venue, M Shed, on Bristol's harbourside
For photos of BQIT:17 please visit:
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