QIPIRC

Highlights 2008

A selection of experimental achievements 2007/08

Each year the QIP IRC management team report to the QIP IRC Board and to EPSRC on the activities of the research groups, highlighting interesting and significant results, publications or achievements. The research highlights are taken from the annual reports we ask each group to submit at the end of March. In 2008, a summary, was compiled of some experimental achievements in three key areas:trapped ions and cold atoms; optical processing and communication; and spins in nanomaterials. It was intended to be illustrative and not an exhaustive overview of all the excellent work that is being carried out by the groups working within the IRC and the following list of recent results was also included:

• Single shot read-out in ion trap has been developed with 99.99% fidelity, compared with the previous world best of 99% (Oxford).

• Spin blockade has been observed in a peapod nanotube, opening the way to single spin read-out in devices of these materials (Oxford, Cambridge).

• All optical CNOT gates have been demonstrated using two heralded fibre sources of photons, with an average logical fidelity of 90%, and in a waveguide quantum circuit, with an average logical fidelity of 94% (Bristol).

• Closed-loop coherent control has been used to mitigate the rate of quantum dephasing in a gas-phase ensemble of potassium dimers, which acts as a model system for testing the general concepts of controlling decoherence (Oxford, Princeton).

• Quantum information has been transferred from electron spins to nuclear spins and back again in phosphorous in silicon, with a storage time 1.75 s and fidelity 82%, and in N@C60 fullerenes, with a storage time of 50 ms and fidelity >50% (Oxford, Princeton).

• The oscillator strength of the exciton in a single InGaN quantum dot has been controlled by an electric field (Oxford, Cambridge).

• Phase amplification of nine coupled proton spins has been demonstrated, paving the way for entanglement amplification of phase in electron spins for supersensors that exceed the standard quantum limit (Oxford).

• Measurement equipment using field programmable gate arrays has been developed for multiphoton experiments, with a fractional clock delay scheme which can time tag with resolution 800 ps, and eventually 300 ps (Bristol).

The expanded scientific reports requested from investigators as part of the quarterly academic report for January to March each year are your chance to show what excellent work you've been doing. If you have an exciting research highlight or publication that you wish to share, make sure it is included in your group's report.