Long-lived electron spin coherence in CdSe/ZnSSe self-assembled quantum   dots
  The electron spin coherence in n-doped and undoped, self-assembled CdSe/Zn(S,Se) quantum dots has been studied by time-resolved pump-probe Kerr rotation. Long-lived spin coherence persisting up to 13 ns after spin orientation has been found in the n-doped quantum dots, outlasting significantly the lifetimes of charge neutral and negatively charged excitons of 350 - 530 ps. The electron spin dephasing time as long as 5.6 ns has been measured in a magnetic field of 0.25 T. Hyperfine interaction of resident electrons with a nuclear spin fluctuations is suggested as the main limiting factor for the dephasing time. The efficiency of this mechanism in II-VI and III-V quantum dots is analyzed. 
M. Syperek, D. R. Yakovlev, I. A. Yugova, J. Misiewicz, I. V. Sedova,   S. V. Sorokin, A. A. Toropov, S. V. Ivanov, and M. Bayer
cond-mat.mes-hall cond-mat.other