Optically induced long-lived electron spin coherence in ZnSe/BeTe type-II quantum wells

The spin coherence of photoexcited electrons in ZnSe/BeTe type-II quantum wells has been investigated by the time-resolved Kerr rotation technique. Fast and efficient escape of photoexcited holes from the ZnSe layers to the BeTe layers suppresses the electron-hole recombination and their exchange interaction. This effect leads to the formation of dense electrons in ZnSe layers and long electron spin dephasing time reaching a value of 6.1 ns at 1.4 K. (C) 2008 American Institute of Physics.