Infrared Spectroscopy and Vibronic Structure of the Nitrogen-Vacancy Center in Diamond

The negatively charged nitrogen-vacancy (NV) color center in diamond has created much recent excitement. Since their ground state can be optically spin-polarized and read-out and they have a long transverse spin relaxation time at room temperature, NV centers are used in an array of applications including quantum computing, sensing, and sub-diffraction-limited imaging. Despite the progress in developing these applications, many of the basic questions about NV centers remain unresolved. We present a pump-probe spectroscopy experiment on the NV infrared transition that sheds light on the vibronic structure of NV centers. From this measurement, we were able to compare the vibronic properties of two NV electronic states and find unexpected differences between them.