The key elements required for quantum information processing are:
- Low error encoding of qubits onto individual quantum systems
- Storage of quantum information for times long compared to gate times
- Controllable two qubit interactions forming fast quantum gates.
Our candidate systems are the paramagnetic colour centres in diamond. They offer at individual spin control and at room temperature very long coherence times compared to quantum gate processing times. The primary objective of this project is to use such defects in nanostructured diamond to implement scalable quantum logic gates, with the prospect of room temperature operation. Such elements rely on electron spin splitting of ground states in specific colour centres in diamond. Read-out of the single electron spin state can be achieved through optical detection of the colour centre strong photoluminescence, which is perfectly photostable even at room temperature.
An order-of-magnitude improvement of the detection efficiency is therefore of crucial importance for achieving single shot read-out of the state of the addressed spin, and is one of the main objectives of the project. Coherent single photon wavepackets are also one of the building blocks for a photon-based quantum processor. Since individual colour centres in diamond have been shown as promising single photon source, temporal coherence of the emitted single photons will be investigated.
The project involves 8 groups, all leading experts in the field of diamond material processing and application of diamond to quantum information. It strongly relies on recent developments in the synthesis and processing of high purity isotopically engineered intrinsic and doped single crystal diamond, the production and functionalization of diamond nanocrystals, and methods of controlled activation of defect centres suitable for quantum computing. Such developments will also benefit to diamond colour centre based single photon sources for quantum cryptography.
Funding SchemeSTREP - Specific Targeted Research Project
SL5 8BP Ascot
CV4 8UW Coventry