Coherent manipulation of coupled electron spins in semiconductor quantum dots.

نویسندگان

  • J R Petta
  • A C Johnson
  • J M Taylor
  • E A Laird
  • A Yacoby
  • M D Lukin
  • C M Marcus
  • M P Hanson
  • A C Gossard
چکیده

We demonstrated coherent control of a quantum two-level system based on two-electron spin states in a double quantum dot, allowing state preparation, coherent manipulation, and projective readout. These techniques are based on rapid electrical control of the exchange interaction. Separating and later recombining a singlet spin state provided a measurement of the spin dephasing time, T2*, of approximately 10 nanoseconds, limited by hyperfine interactions with the gallium arsenide host nuclei. Rabi oscillations of two-electron spin states were demonstrated, and spin-echo pulse sequences were used to suppress hyperfine-induced dephasing. Using these quantum control techniques, a coherence time for two-electron spin states exceeding 1 microsecond was observed.

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عنوان ژورنال:
  • Science

دوره 309 5744  شماره 

صفحات  -

تاریخ انتشار 2005