Microscopic control of $^{29}$Si nuclear spins near phosphorus donors in   silicon
  We demonstrate an efficient control of $^{29}$Si nuclear spin orientation for specific lattice sites near $^{31}$P donors in silicon crystals at temperatures below 1 K and in high magnetic field of 4.6 T. Excitation of the forbidden electron-nuclear transitions leads to a pattern of narrow holes and peaks in the ESR lines of $^{31}$P. The pattern originates from dynamic polarization the $^{29}$Si nuclear spins near the donors via the solid effect. This method can be used for initialization of qubits based on $^{29}$Si nuclear spins in the all-silicon quantum computer. In comparison, polarization of $^{29}$Si performed by pumping the allowed ESR transitions, did not create any patterns. Instead, a single narrow spectral hole was burnt in the ESR line. The difference is explained by a rapid spin diffusion during the microwave pumping of the allowed transitions. 
J. J\"arvinen, D. Zvezdov, J. Ahokas, S. Sheludyakov, O. Vainio, L.   Lehtonen, S. Vasiliev, Y. Fujii, S. Mitsudo, T. Mizusa...
physics.atm-clus cond-mat.mes-hall