We study the coupling of a single nitrogen-vacancy center in diamond to a nearby single nitrogen defect at room temperature. The magnetic dipolar coupling leads to a splitting in the electron spin resonance frequency of the nitrogen-vacancy center, allowing readout of the state of a single nitrogen electron spin. At magnetic fields where the spin splitting of the two centers is the same we observe a strong polarization of the nitrogen electron spin. The amount of polarization can be controlled by the optical excitation power. We combine the polarization and the readout in time-resolved pump-probe measurements to determine the spin relaxation time of a single nitrogen electron spin. Finally, we discuss indications for hyperfine-induced polarization of the nitrogen nuclear spin.
@article{arxiv.quant-ph/0605179,
title = {Polarization and readout of coupled single spins in diamond},
author = {R. Hanson and F. M. Mendoza and R. J. Epstein and D. D. Awschalom},
journal= {arXiv preprint arXiv:quant-ph/0605179},
year = {2007}
}