Control and detection of singlet-triplet mixing in a random nuclear field
Control and detection of singlet-triplet mixing in a random nuclear field
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DOI：
10.1126/science.1113719
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发表时间：
2005-08-26
期刊：
影响因子：
56.9
通讯作者：
Vandersypen, LMK
中科院分区：
文献类型：
--
作者：
Koppens, FHL;Folk, JA;Vandersypen, LMK
我们观察到双量子点中双电子单重态和三重态之间的混合，这是由与主体半导体中核自旋的相互作用引起的。当我们施加小磁场或增加点间隧道耦合并从而单线态-三线态分裂时，这种混合被抑制。涉及三重态和单重态之间跃迁的电子传输反过来又使原子核极化，导致显着的双稳定性。我们从波动核场中提取[对 25 纳秒的时间平均自旋相干时间 T*(2) 的模拟。因此，电子-核相互作用的控制对于单个电子自旋的相干操纵至关重要。
We observed mixing between two-electron singlet and triplet states in a double quantum dot, caused by interactions with nuclear spins in the host semiconductor. This mixing was suppressed when we applied a small magnetic field or increased the interdot tunnel coupling and thereby the singlet-triplet splitting. Electron transport involving transitions between triplets and singlets in turn polarized the nuclei, resulting in marked bistabilities. We extract from the fluctuating nuclear field a [imitation on the time-averaged spin coherence time T*(2) of 25 nanoseconds. Control of the electron-nuclear interaction will therefore be crucial for the coherent manipulation of individual electron spins.