A Controlled Phase Gate with Nitrogen-Vacancy Centers in Nanocrystal Coupled to a Silica Microsphere Cavity

We show how a controlled phase gate, induced by adiabatic passage of dark states, can be implemented with the nitrogen-vacancy defects in nanocrystal coupled to the optical whispering gallery mode in a silica microsphere cavity. The gate presented is robust to the fluctuations of the experimental parameters compared to the dynamical and geometric phases gates. The feasibility of this scheme is characterized by exact numerical simulations that incorporate various sources of experiment noise. The results demonstrate the practicality by way of current experimental technologies.