Researchers have announced major progress in the development of synthetic diamond.
The solution would be suitable for the production of quantum computers capable of operating at room temperature. Element Six, along with researchers at the Universities of Paris and Stuttgart, have developed synthesis processes based on chemical vapour deposition (cvd) that can produce ultrapure isotopically controlled single crystal diamond with a low concentration of paramagnetic impurities. Daniel Twitchen, senior researcher at Element Six, said: "This isotopically engineered diamond is essentially the first quantum grade purity diamond ever produced and marks a milestone for synthetic diamond produced by a cvd process." The results highlight the progress of research carried out under a three year project called Engineered Quantum Information in Nanostructured Diamond or EQUIND which started in early 2007. EQUIND is part of the European Union's FET Open Funding Programme, aimed at studying the potential of future and emerging technologies that may have an impact on society or industry. The project's main aim is to establish whether specific optical features identified in diamond can be used as the basic elements for quantum computers and single photon sources. One of the requirements of practical quantum devices is that the individual quantum bits, or qubits need to store information for sufficient time to make many computational operations. Any unintentional defects with paramagnetic spin in the diamond can result in the qubits rapidly losing their quantum information, severely limiting the number of possible computations. The researchers managed to increase 'coherence time' which is one of the many challenges to building practical computers. This required developing quantum purity diamond with a low defect spin concentration. The EQUIND consortium report, single electron spins having a room temperature spin dephasing time of 1.8ms, the longest ever observed in a solid state system at room temperature. Diamond with these properties is also applicable to research into a new type of nanometre scale magnetic sensors that could be used in biological imaging or diamond magnetometers which could detect magnetic fields associated with the ion flow through membrane channels in cells.