%0 Journal Article %J Physical Review Letters %D 2008 %T Coherence of an optically illuminated single nuclear spin qubit %A Liang Jiang %A M. V. Gurudev Dutt %A Emre Togan %A Lily Childress %A Paola Cappellaro %A J. M. Taylor %A Mikhail D. Lukin %X We investigate the coherence properties of individual nuclear spin quantum bits in diamond [Dutt et al., Science, 316, 1312 (2007)] when a proximal electronic spin associated with a nitrogen-vacancy (NV) center is being interrogated by optical radiation. The resulting nuclear spin dynamics are governed by time-dependent hyperfine interaction associated with rapid electronic transitions, which can be described by a spin-fluctuator model. We show that due to a process analogous to motional averaging in nuclear magnetic resonance, the nuclear spin coherence can be preserved after a large number of optical excitation cycles. Our theoretical analysis is in good agreement with experimental results. It indicates a novel approach that could potentially isolate the nuclear spin system completely from the electronic environment. %B Physical Review Letters %V 100 %8 2008/2/19 %G eng %U http://arxiv.org/abs/0707.1341v2 %N 7 %! Phys. Rev. Lett. %R 10.1103/PhysRevLett.100.073001