Coherent manipulation of coupled electron spins in semiconductor quantum dots
Coherent manipulation of coupled electron spins in semiconductor quantum dots
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DOI：
10.1126/science.1116955
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发表时间：
2005-09-30
期刊：
影响因子：
56.9
通讯作者：
Gossard, AC
中科院分区：
文献类型：
--
作者：
Petta, JR;Johnson, AC;Gossard, AC
我们展示了基于双量子点中的双电子自旋态的量子二能级系统的相干控制，允许状态制备，相干操纵和投影读出。这些技术基于交换相互作用的快速电控制。分离并随后重新组合单重态自旋提供了类似于10纳秒的自旋退相时间T-2 * 的测量值，这受到与砷化镓宿主核的超精细相互作用的限制。证明了双电子自旋态的拉比振荡，并使用自旋回波脉冲序列来抑制超精细诱导的退相。利用这些量子控制技术，观察到两个电子自旋态的相干时间超过1微秒。
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, T-2*, of similar to 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.