Fine structure of excited state in nitrogen-vacancy centre of diamond

Gregory D. Fuchs, V. V. Dobrovitski, D.M. Toyli +4 more

Robert Chapman, Taras Plakhotnik

N. V. Nguyen, Juil Hwang, Seunghyun Bang +4 more

Philippe Tamarat, N. B. Manson, J. P. Harrison +9 more

We map out the first excited state sublevel structure of single nitrogen-vacancy (NV) colour centres in diamond. The excited state is an orbital doublet where one branch supports an efficient cycling transition, while the other can simultaneously support fully allowed optical Raman spin-flip transitions. This is crucial for the success of many recently proposed quantum information applications of the NV defects. We further find that an external electric field can be used to completely control the optical properties of a single centre. Finally, a group theoretical model is developed that explains the observations and provides good physical understanding of the excited state structure.

Lachlan J. Rogers, R L McMurtrie, Matthew J. Sellars +1 more

The emission intensity of diamond samples containing negatively charged nitrogen-vacancy centres are measured as a function of magnetic field along the ⟨111⟩ direction for various temperatures. At low temperatures the responses are sample and stress dependent and can be modelled in terms of the previous understanding of the 3 E excited state fine structure which is strain dependent. At room temperature the responses are largely sample and stress independent, and modelling involves invoking a strain independent excited state with a single zero field spin-level splitting of 1.42 GHz. The change in behaviour is attributed to a temperature dependent averaging process over the components of the excited state orbital doublet. It decouples orbit and spin and at high temperature the spin levels become independent of any orbit splitting. One significant implication of this averaging is that it simplifies the development of room temperature applications.

Denis Antonov, Jörg Wrachtrup, Gabriel Bester