%0 Journal Article
%T The Infrared Absorption Band and Vibronic Structure of the Nitrogen-Vacancy Center in Diamond
%A P. Kehayias
%A M. W. Doherty
%A D. English
%A R. Fischer
%A A. Jarmola
%A K. Jensen
%A N. Leefer
%A P. Hemmer
%A N. B. Manson
%A D. Budker
%J Physics
%D 2013
%I arXiv
%R 10.1103/PhysRevB.88.165202
%X Negatively-charged nitrogen-vacancy (NV$^-$) color centers in diamond have generated much interest for use in quantum technology. Despite the progress made in developing their applications, many questions about the basic properties of NV$^-$ centers remain unresolved. Understanding these properties can validate theoretical models of NV$^-$, improve their use in applications, and support their development into competitive quantum devices. In particular, knowledge of the phonon modes of the $^1A_1$ electronic state is key for understanding the optical pumping process. Using pump-probe spectroscopy, we measured the phonon sideband of the ${^1}E\rightarrow{^1}A_1$ electronic transition in the NV$^-$ center. From this we calculated the ${^1}E\rightarrow{^1}A_1$ one-phonon absorption spectrum and found it to differ from that of the ${^3}E\rightarrow{^3}A_2$ transition, a result which is not anticipated by previous group-theoretical models of the NV$^-$ electronic states. We identified a high-energy 169 meV localized phonon mode of the $^1A_1$ level.
%U http://arxiv.org/abs/1301.6197v2