CVD diamond for spintronics

The ability to minimise, control and manipulate defects in CVD diamond has grown rapidly over the last ten years. The application which best illustrates this is probably that of quantum information processing (QIP) or ‘diamond spintronics’. QIP is a rapidly growing area of research, covering diverse activities from computing and code breaking to encrypted communication. All these applications need ‘quantum bits’ or qubits where the quantum information can be maintained and controlled. Controlled defects in an otherwise high perfection diamond lattice are rapidly becoming a leading contender for qubits, and offer many advantages over alternative solutions. The most promising defect is the NV− defect whose unique properties allow the state of its electron spin to be optically written to and read from. Substantial developments in the synthesis of CVD diamond have produced diamond lattices with a high degree of perfection, such that the electron spin of this centre exhibits very long room temperature decoherence times (T2) in excess of 1 ms. This paper gives a brief review of the advantages and challenges of using CVD diamond as a qubit host. Lastly the various qubit applications being considered for diamond are discussed, highlighting the current state of development including the recent development of high sensitivity magnetometers.

Research Highlights
► The state-of-the art in CVD diamond materials as a qubit host is discussed.
► High purity polycrystalline diamond has been grown with isolated NV- defect centres.
► These can show long decoherence times up to 600 µs.