Quantum Communications Hub, EPSRC

Timothy P. Spiller

The Quantum Communications Hub is one of four Hubs comprising the research and development end of the UK National Quantum Technologies Programme. This programme is now in its second phase (2019-2024), following a successful first phase that ran 2014-2019. Our Hub provides the UK focus for the quantum communications sector. In this talk I'll provide a brief overview of the Hub's phase 1 developments, which mainly concentrated on progressing quantum key distribution (QKD) towards wider application. The grand vision of the phase 2 Hub is integrated secure quantum communications at all distance scales. For practicality and flexibility, this involves free-space communications at the shortest distance scales, fibre-based communications at the metrolpolitan and inter-city distance scales covered by current fibre networking, and free-space communications to support the very longest distances required for global reach. I'll outline the Hub activities on short-range consumer QKD, fibre networking and long distance satellite-to-ground QKD. I'll also cover our work on new protocols, hybrid secure communications, standards and components. http://www.quantumcommshub.net/

Venkateswaran Kasirajan

Ajey Lele

David Lowndes

We present a Quantum Key Distribution system comprising a hand held transmitter device (Alice) and a fixed terminal (Bob). The devices are highly asymmetrical with as much functionality as possible placed into the Bob terminal (a 4u 19in. rack) which is much less restricted on its size. The small size (80x50x10mm) and relatively low complexity will allow the hand held Alice to be cheaply mass produced and therefore widely available. A potential use for this technology would be as a method to allow the general public to benefit from a wider metropolitan or national QKD network by establishing key with trusted network nodes. The Alice device optics comprise 4 pulsed 300um LEDs behind polarizers to produce the photon states for the BB84 protocol. Light from the LEDs is combined and spatially filtered using a single mode fibre, the output of which is collimated by a lens at the optical output of the device. The device is currently controlled via USB by a PC or mobile phone. The Bob terminal is split into two modules; broadly categorized as “optical” and “processing”. The optical module contains beam splitters for state discrimination and photon detection. The processing module contains a PC, wireless router, time-tagging electronics and power supply. The modular approach allows for a flexible platform for different QKD experiments, for example change of wavelength or protocol would involve switching out only the optical module. This work forms part of the Quantum Communications hub and was carried out with EPSRC funding (Quantum Communications Hub, grant no. EP/M013472/1).

Gianfranco Cariolaro

Philip Sibson, David Lowndes, Stefan Frick +16 more