Single-spin manipulation in a double quantum dot with micromagnet
Single-spin manipulation in a double quantum dot with micromagnet
复制标题
用微磁体对双量子点进行单自旋操纵
DOI：
10.1103/physrevb.90.235311
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发表时间：
2014
影响因子：
3.7
通讯作者：
and Daniel Loss
中科院分区：
文献类型：
--
作者：
Stefano Chesi;Ying-Dan Wang;Jun Yoneda;Tomohiro Otsuka;Seigo Tarucha;and Daniel Loss
在Coish and Loss [Phys. Rev. B 75，161302（2007）PRBMDO 1098 -012110.1103/PhysRevB.75.161302]中讨论了通过利用交换相互作用和高度不均匀的磁场来操纵双量子点中的单自旋。然而，在横向双点的当前设计中，通过微磁体的倾斜场难以实现这种大的不均匀性。因此，我们研究了一个类似的自旋操纵计划直接适用于现实的GaAs双点设置。我们估计，典型的门时间，实现在单重态-三重态的反交叉诱导的不均匀的微磁场，可以是几纳秒。我们讨论了初始化，读出，和单自旋门通过适当的选择失谐脉冲和改进的几何形状的优化。我们还研究了核失相和电荷噪声的影响。后者引起失谐和隧穿振幅的波动。我们的研究结果表明，该方案是一个很有前途的实现快速单自旋操作的方法。
The manipulation of single spins in double quantum dots by making use of the exchange interaction and a highly inhomogeneous magnetic field was discussed in Coish and Loss [Phys. Rev. B 75, 161302 (2007)PRBMDO1098-012110.1103/PhysRevB.75.161302]. However, such large inhomogeneity is difficult to achieve through the slanting field of a micromagnet in current designs of lateral double dots. Therefore, we examine an analogous spin manipulation scheme directly applicable to realistic GaAs double dot setups. We estimate that typical gate times, realized at the singlet-triplet anticrossing induced by the inhomogeneous micromagnet field, can be a few nanoseconds. We discuss the optimization of initialization, read-out, and single-spin gates through suitable choices of detuning pulses and an improved geometry. We also examine the effect of nuclear dephasing and charge noise. The latter induces fluctuations of both detuning and tunneling amplitude. Our results suggest that this scheme is a promising approach for the realization of fast single-spin operations.