€3 million to solve the long-distance quantum communication problem

The problem of sending information in single quantum particles over global distances could be a step closer thanks to grants of over €3 million that have been awarded to researchers in the University of Bristol’s Quantum Photonics group.

Ruth Oulton and Professor John Rarity at the Centre for Quantum Photonics have been awarded a €2 million Future and Emerging Technologies grant from the European Commission and a €1.1 million CHIST-ERA award from European national funding agencies, including the EPSRC.

The use of particles of light, photons, to encode and send information could revolutionise the way we secure all internet transactions, while computing using photons promises much faster ways of tackling hard problems. The aim of both these projects is to use semiconductor devices to mediate the interaction between photons providing a quantum memory and quantum logic gates to extend these quantum applications to longer distances and harder problems.

The challenge for the CHIST-ERA project, the Solid-State Quantum Network (SSQN), led by Professor John Rarity, is to use semiconductor devices, the same technology as the lasers used conventional tele, on the nanoscale.  Nanosized "quantum dots" trap a single electron, which act as the memory for a quantum repeater.  The single electrons store information for a millionth of a second, enough for a set of base-stations, spaced by 100 km to transfer the information in a single photon over 1,000 km.

The Bristol team wish to go even further.  In the FP7 EU project, Spin Photon Angular Momentum Transfer for Quantum Enabled Technologies (SPANGL4Q), led by Ruth Oulton, the team introduce novel designs and techniques into the semiconductor devices.