TY - JOUR T1 - Dynamic Nuclear Polarization in Double Quantum Dots JF - Physical Review Letters Y1 - 2010 A1 - Michael Gullans A1 - J. J. Krich A1 - J. M. Taylor A1 - H. Bluhm A1 - B. I. Halperin A1 - C. M. Marcus A1 - M. Stopa A1 - A. Yacoby A1 - M. D. Lukin AB - We theoretically investigate the controlled dynamic polarization of lattice nuclear spins in GaAs double quantum dots containing two electrons. Three regimes of long-term dynamics are identified, including the build up of a large difference in the Overhauser fields across the dots, the saturation of the nuclear polarization process associated with formation of so-called "dark states," and the elimination of the difference field. We show that in the case of unequal dots, build up of difference fields generally accompanies the nuclear polarization process, whereas for nearly identical dots, build up of difference fields competes with polarization saturation in dark states. The elimination of the difference field does not, in general, correspond to a stable steady state of the polarization process. VL - 104 UR - http://arxiv.org/abs/1003.4508v2 CP - 22 J1 - Phys. Rev. Lett. U5 - 10.1103/PhysRevLett.104.226807 ER -