The understanding of the coherence properties of photons emitted from negatively charged nitrogen-vacancy (NV)
centers in diamond is essential for the success of quantum information applications based on indistinguishable
photons. Here we study both the polarization of photons emitted from and the linewidth of photons absorbed by
single NV centers as a function of temperature T. We find that for T < 100 K the main dephasing mechanism
contributing to the linewidth broadening is phonon-mediated population transfer between the two excited orbital
states. The observed T5 temperature dependence of the population transfer rate and linewidth is experimental
evidence of a dynamic Jahn-Teller effect in the excited states.
We discuss how Very Large Scale Integration (VLSI) fabrication techniques can be used to build scalable solid-state quantum computers in diamond with either room temperature operation, or low temperature operation with photonic control. For this discussion we consider nitrogen-vacancy (NV) color centers where the qubits are electron and/or nuclear spins. To achieve scalability the NV centers are placed in well-defined locations using ion implantation, and are
controlled using optical and/or microwave excitation as well as localized static electric and/or magnetic fields.
In this paper we present a theoretical study of the effect of a microwave field on an EIT feature. The EIT feature is associated with the well-known three-level Λ type configuration where a pump and probe laser field couples two separate optical transitions. In addition to these two laser fields, there is a microwave field which drives one of the two lower levels of the Λ type three-level system to another hyperfine level. The EIT feature is studied as a function of microwave field frequency and intensity. Our results show that the presence of a microwave field can dramatically modify the EIT feature. When microwave is resonant with the hyperfine transition, the EIT feature can be split into two EIT features. When it is off resonant with the hyperfine transition, it causes a frequency shift of the EIT feature, reminiscent of the well-known light shift effect.