Fast Electrical Control of Single Electron Spins in Quantum Dots with   Vanishing Influence from Nuclear Spins
  We demonstrate fast universal electrical spin manipulation with inhomogeneous magnetic fields. With fast Rabi frequency up to 127 MHz, we leave the conventional regime of strong nuclear-spin influence and observe a spin-flip fidelity > 96%, a distinct chevron Rabi pattern in the spectral-time domain, and spin resonance linewidth limited by the Rabi frequency, not by the dephasing rate. In addition, we establish fast z-rotations up to 54 MHz by directly controlling the spin phase. Our findings will significantly facilitate tomography and error correction with electron spins in quantum dots. 
J. Yoneda, T. Otsuka, T. Nakajima, T. Takakura, T. Obata, M.   Pioro-Ladri\`ere, H. Lu, C. Palmstr{\o}m, A. C. Gossard and S...
cond-mat.mes-hall