A versatile method for polarizing single nuclear spins in diamond was reported. It

was based upon the optical pumping of a single nitrogen-vacancy defect and

mediated by a level anti-crossing in its excited state. A nuclear-spin polarization

higher than 98% was achieved at room temperature for the 15N nuclear spin

associated with the nitrogen-vacancy center; corresponding to a micro-K effective

nuclear-spin temperature. Simultaneous initialization of two nuclear spins in the

vicinity of a nitrogen-vacancy defect was then demonstrated.

Dynamic Polarization of Single Nuclear Spins by Optical Pumping of Nitrogen-

Vacancy Colour Centers in Diamond at Room Temperature. V.Jacques,

P.Neumann, J.Beck, M.Markham, D.Twitchen, J.Meijer, F.Kaiser,

G.Balasubramanian, F.Jelezko, J.Wrachtrup: Physical Review Letters ,

2009,102[5], 057403