Dynamic nuclear polarization with single electron spins.
Dynamic nuclear polarization with single electron spins.
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DOI：
10.1103/physrevlett.100.067601
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发表时间：
2007-09
影响因子：
8.6
通讯作者：
J. Petta;J. Petta;Jacob M. Taylor;Jacob M. Taylor;A. C. Johnson;A. Yacoby;Mikhail D. Lukin;Charles Marcus;M. Hanson;A. Gossard
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文献类型：
--
作者：
J. Petta;J. Petta;Jacob M. Taylor;Jacob M. Taylor;A. C. Johnson;A. Yacoby;Mikhail D. Lukin;Charles Marcus;M. Hanson;A. Gossard
我们用脉冲门控制单重态(S)和m(S)=+1三重态(T+)附近的双电子自旋态，从而极化了砷化镓双量子点中的核自旋。初始化的S态与T+态周期性地产生共振，在T+态中，超精细场驱动S和T+之间的快速旋转，使电子自旋“翻转”，原子核自旋“翻转”。由此产生的Overhauser场接近80mT，符合一个简单的速率方程模型。开发了一种自限脉冲序列，该序列允许使用栅极电压来设置稳态核极化。
We polarize nuclear spins in a GaAs double quantum dot by controlling two-electron spin states near the anticrossing of the singlet (S) and m(S)= +1 triplet (T+) using pulsed gates. An initialized S state is cyclically brought into resonance with the T+ state, where hyperfine fields drive rapid rotations between S and T+, "flipping" an electron spin and "flopping" a nuclear spin. The resulting Overhauser field approaches 80 mT, in agreement with a simple rate-equation model. A self-limiting pulse sequence is developed that allows the steady-state nuclear polarization to be set using a gate voltage.