Combined optical and microwave approach for performing quantum spin operations on the nitrogen-vacancy center in diamond

Electron spin echoes were performed on nitrogen-vacancy (N-V) centers in diamond using optical polarization and detection and 35 GHz microwave control. The experiments demonstrate an approach to quantum information in the solid state. A phase memory time of 3.6 μs was measured, and coupling of the electronic spin to the ¹⁴N nuclear spin was observed. Because of the favorable properties of the N-V center, interesting extensions of these single-qubit operations can be proposed.