...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Physical review. B, Condensed Matter And Materals Physics >Signatures of long-range spin-spin interactions in an (In,Ga)As quantum dot ensemble
【24h】

Signatures of long-range spin-spin interactions in an (In,Ga)As quantum dot ensemble

机译：（In，Ga）As量子点集合中远程自旋-自旋相互作用的特征

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We present an investigation of the electron spin dynamics in an ensemble of singly charged semiconductor quantum dots subject to an external magnetic field and laser pumping with circularly polarized light. The spectral laser width is tailored such that ensembles with an increasing number of quantum dots are coherently pumped. Surprisingly, the dephasing time T* of the electron spin polarization depends only weakly on the laser spectral width. These findings can be consistently explained by a cluster theory of coupled quantum dots with a long-range electronic spin-spin interaction. We present a numerical simulation of the spin dynamics based on the central spin model that includes a quantum mechanical description of the laser pulses as well as a time-independent Heisenberg interaction between each pair of electron spins. We discuss the individual dephasing contributions stemming from the Overhauser field, the distribution of the electron g factors, and the electronic spin-spin interaction as well as the spectral width of the laser pulse. This analysis reveals counterbalancing effects on the total dephasing time when increasing the spectral laser width. On one hand, the increasing deviations of the electron g factors reduce the dephasing time. On the other hand, more electron spins are coherently pumped and synchronize due to the electronic spin-spin interaction which extends the dephasing time. We find an excellent agreement between the experimental data and the dephasing time in the simulation using an exponential distribution of Heisenberg couplings with a mean value (J) over bar approximate to 0.26 mu eV.
机译：我们提出了对单电荷半导体量子点的整体中电子自旋动力学的研究，该量子点受到外部磁场的影响和圆偏振光的激光泵浦。调整光谱激光器的宽度，以使具有越来越多的量子点的集合被相干地泵浦。令人惊讶的是，电子自旋极化的相移时间T *仅弱地取决于激光光谱宽度。这些发现可以通过具有长程电子自旋-自旋相互作用的耦合量子点的簇理论来一致地解释。我们基于中央自旋模型提出了自旋动力学的数值模拟，其中包括激光脉冲的量子力学描述以及每对电子自旋之间与时间无关的海森堡相互作用。我们讨论了由于Overhauser场，电子g因子的分布以及电子自旋-自旋相互作用以及激光脉冲的光谱宽度而引起的各个相移贡献。该分析揭示了增加光谱激光宽度时，对总移相时间的平衡作用。一方面，电子g因子的增加的偏差减少了移相时间。另一方面，由于电子自旋-自旋相互作用而延长相移时间，更多的电子自旋被相干地泵浦并同步。我们在海森堡偶合器的指数分布中使用均值（J）的海森堡偶合器的指数分布在模拟中的实验数据和相移时间之间找到了极好的一致性，其条形上的平均值（J）约为0.26 mu eV。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号